Tableview height issue after device orientation changed

I am showing a view Controller with a self sizing tableview inside a Container view. See green color view in image 1.

If the device orientation changed to Landscape mode, the UI has no issues and shows exactly as I want. See below image.

But if I changed orientation back to portrait mode, then the height of the tableview inside Containerview doesn't get updated.I have added a purple background color to tableview. See below image.

I have tried view.setNeedsLayout(), containerView.setNeedsLayout(), view.layoutIfNeeded() inside the viewWillTransition function. But still no success. Please some one help to fix this issue.

Update: Here is how I add subview to the container view

func showMCQs() {
    mcqKit = MCQKit()
    mcqKit!.configureMCQV2()
    addChild(MCQKit.mcqV2Controller)
    containerView.addSubview(MCQKit.mcqV2Controller.view)
    MCQKit.mcqV2Controller.didMove(toParent: self)
    MCQKit.mcqV2Controller.view.anchor(top: containerView.topAnchor, left: containerView.leftAnchor, bottom: containerView.bottomAnchor, right: containerView.rightAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: nil, height: nil, centerX: nil, centerY: nil)
}
extension UIView {
func anchor(top: NSLayoutYAxisAnchor?, left: NSLayoutXAxisAnchor?, bottom: NSLayoutYAxisAnchor?, right: NSLayoutXAxisAnchor?,  paddingTop: CGFloat?, paddingLeft: CGFloat?, paddingBottom: CGFloat?, paddingRight: CGFloat?, width: CGFloat?, height: CGFloat?, centerX: NSLayoutXAxisAnchor?, centerY: NSLayoutYAxisAnchor?) {
    translatesAutoresizingMaskIntoConstraints = false
    
    if let safeTop = top, let safePaddingTop = paddingTop {
        topAnchor.constraint(equalTo: safeTop, constant: safePaddingTop).isActive = true
    }
    
    if let safeLeft = left, let safePaddingLeft = paddingLeft {
        leftAnchor.constraint(equalTo: safeLeft, constant: safePaddingLeft).isActive = true
    }
    
    if let safeBottom = bottom, let safePaddingBottom = paddingBottom  {
        bottomAnchor.constraint(equalTo: safeBottom, constant: -safePaddingBottom).isActive = true
    }
    
    if let safeRight = right, let safePaddingRight = paddingRight  {
        rightAnchor.constraint(equalTo: safeRight, constant: -safePaddingRight).isActive = true
    }
    
    if let safeWidth = width, safeWidth != 0 {
        widthAnchor.constraint(equalToConstant: safeWidth).isActive = true
    }
    
    if let safeHeight = height, safeHeight != 0{
        heightAnchor.constraint(equalToConstant: safeHeight).isActive = true
    }
    
    if let centerX = centerX {
        centerXAnchor.constraint(equalTo: centerX).isActive = true
    }
    
    if let centerY = centerY {
        centerYAnchor.constraint(equalTo: centerY).isActive = true
    }
}

Below is the code for the self sizing tableview.

class CustomTableView: UITableView {

// Self sizing tableView
override public func layoutSubviews() {
    super.layoutSubviews()
    if bounds.size != intrinsicContentSize {
        invalidateIntrinsicContentSize()
    }
}

override public var intrinsicContentSize: CGSize {
    layoutIfNeeded()
    return contentSize
}

}

Really difficult to try and guess where you're setup is failing, without seeing all of your layout / constraints / etc.

So, here is a (really, really) quick example - with 3 "Quiz Questions" - that I think comes close to what you're going for... rotating the device is properly handled.

ScrollView background is green, "container" view background is yellow, child controller view background is light-blue. Each element is constrained with small constants to make it easier to see the framing.

Rotated:

Scrolling, when needed:

struct QuizQuestion {
    var title: String = ""
    var answers: [String] = []
}

class AnswerCell: UITableViewCell {
    
    static let identifier: String = "AnswerCell"
    
    public var theData: String = "" {
        didSet {
            label.text = theData
        }
    }
    
    private let label = UILabel()
    
    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        commonInit()
    }
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        commonInit()
    }
    private func commonInit() {
        label.translatesAutoresizingMaskIntoConstraints = false
        contentView.addSubview(label)
        let g = contentView.layoutMarginsGuide
        NSLayoutConstraint.activate([
            label.topAnchor.constraint(equalTo: g.topAnchor),
            label.leadingAnchor.constraint(equalTo: g.leadingAnchor),
            label.trailingAnchor.constraint(equalTo: g.trailingAnchor),
            label.bottomAnchor.constraint(equalTo: g.bottomAnchor),
        ])
        
        // it's a multiline label
        label.numberOfLines = 0
        
        label.font = .systemFont(ofSize: 16.0, weight: .regular)
    }
    
}

class CustomTableView: UITableView {
    
    // Self sizing tableView
    override public func layoutSubviews() {
        super.layoutSubviews()
        if bounds.size != intrinsicContentSize {
            invalidateIntrinsicContentSize()
        }
    }
    
    override public var intrinsicContentSize: CGSize {
        layoutIfNeeded()
        return contentSize
    }
}

class TheParentVC: UIViewController {
    
    var someData: [QuizQuestion] = []
    let containerView = UIView()
    var childVC: TheChildVC!
    var curCard: Int = -1
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        view.backgroundColor = .systemBackground
        
        // get some sample data
        someData = sampleData()
        
        let scrollView = UIScrollView()
        
        var cfg = UIButton.Configuration.filled()
        cfg.title = "Next Card"
        let btn = UIButton(configuration: cfg, primaryAction: UIAction() { _ in
            self.showNextCard()
        })

        for v in [scrollView, containerView, btn] {
            v.translatesAutoresizingMaskIntoConstraints = false
        }
        
        scrollView.addSubview(containerView)
        scrollView.addSubview(btn)
        view.addSubview(scrollView)
        
        let g = view.safeAreaLayoutGuide
        let cg = scrollView.contentLayoutGuide
        let fg = scrollView.frameLayoutGuide
        
        NSLayoutConstraint.activate([

            scrollView.topAnchor.constraint(equalTo: g.topAnchor, constant: 8.0),
            scrollView.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 8.0),
            scrollView.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -8.0),
            scrollView.bottomAnchor.constraint(equalTo: g.bottomAnchor, constant: -8.0),

            containerView.topAnchor.constraint(equalTo: cg.topAnchor, constant: 8.0),
            containerView.leadingAnchor.constraint(equalTo: cg.leadingAnchor, constant: 8.0),
            containerView.trailingAnchor.constraint(equalTo: cg.trailingAnchor, constant: -8.0),
            
            btn.topAnchor.constraint(equalTo: containerView.bottomAnchor, constant: 20.0),
            btn.centerXAnchor.constraint(equalTo: containerView.centerXAnchor, constant: 0.0),
            btn.bottomAnchor.constraint(equalTo: cg.bottomAnchor, constant: -20.0),
            
            containerView.widthAnchor.constraint(equalTo: fg.widthAnchor, constant: -16.0),
        ])
        
        showMCQs()
        
        // so we can see the framing
        scrollView.backgroundColor = UIColor(white: 0.9, alpha: 1.0)
        scrollView.backgroundColor = UIColor(red: 0.6, green: 0.8, blue: 0.6, alpha: 1.0)
        containerView.backgroundColor = .systemYellow
        
        // setup the first card
        showNextCard()
    }
    
    func showMCQs() {
        childVC = TheChildVC()
        guard let cView = childVC.view else { fatalError("Invalid setup!") }
        cView.translatesAutoresizingMaskIntoConstraints = false
        containerView.addSubview(cView)
        NSLayoutConstraint.activate([
            cView.topAnchor.constraint(equalTo: containerView.topAnchor, constant: 8.0),
            cView.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 8.0),
            cView.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: -8.0),
            cView.bottomAnchor.constraint(equalTo: containerView.bottomAnchor, constant: -8.0),
        ])
        childVC.didMove(toParent: self)
        
        // see if you can find something in MCQKit that is not being setup
        //  the same way as above
//      mcqKit = MCQKit()
//      mcqKit!.configureMCQV2()
//      addChild(MCQKit.mcqV2Controller)
//      containerView.addSubview(MCQKit.mcqV2Controller.view)
//      MCQKit.mcqV2Controller.didMove(toParent: self)
//      MCQKit.mcqV2Controller.view.anchor(top: containerView.topAnchor, left: containerView.leftAnchor, bottom: containerView.bottomAnchor, right: containerView.rightAnchor, paddingTop: 0, paddingLeft: 0, paddingBottom: 0, paddingRight: 0, width: nil, height: nil, centerX: nil, centerY: nil)
    }
    
    func showNextCard() {
        curCard += 1
        childVC.currentData = someData[curCard % someData.count]
    }
    
    func sampleData() -> [QuizQuestion] {
        let questions: [String] = [
            "Is this the first question?",
            "How many answers are there to choose from for this question (number 2 of 3 from our sample quiz data)?",
            "If this is the last question, does it look like the layout is working as desired?",
        ]
        let answers: [[String]] = [
            ["Yes", "No"],
            ["1", "2", "3", "4"],
            [
                "Yes, it looks like it.",
                "Yes, it even appears that variable-height cells are being handled correctly.",
                "No, I though it would work someother way, but I can't explain how.",
                "Maybe, but I'd rather not commit.",
                "I'm just here to show it works with more than 4 answers (so now we've seen 2, 4 and 5 answer quiz questions).",
            ]
        ]
        var a: [QuizQuestion] = []
        for (q, aa) in zip(questions, answers) {
            a.append(QuizQuestion(title: q, answers: aa))
        }
        return a
    }
}

class TheChildVC: UIViewController, UITableViewDataSource, UITableViewDelegate {
    
    var currentData: QuizQuestion = QuizQuestion() {
        didSet {
            titleLabel.text = currentData.title
            theAnswers = currentData.answers
            tableView.reloadData()
        }
    }
    var theAnswers: [String] = []
    
    let titleLabel = UILabel()
    let tableView = CustomTableView()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .init(red: 0.6, green: 0.85, blue: 1.0, alpha: 1.0)
    
        var cfg = UIButton.Configuration.filled()
        cfg.title = "Submit"
        let btn = UIButton(configuration: cfg, primaryAction: UIAction() { _ in
            
        })
        
        titleLabel.numberOfLines = 0
        titleLabel.font = .systemFont(ofSize: 20.0, weight: .regular)

        for v in [titleLabel, tableView, btn] {
            v.translatesAutoresizingMaskIntoConstraints = false
            view.addSubview(v)
        }
        
        NSLayoutConstraint.activate([

            titleLabel.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 12.0),
            titleLabel.leadingAnchor.constraint(equalTo: self.view.leadingAnchor, constant: 8.0),
            titleLabel.trailingAnchor.constraint(equalTo: self.view.trailingAnchor, constant: -8.0),

            tableView.topAnchor.constraint(equalTo: titleLabel.bottomAnchor, constant: 12.0),
            tableView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor, constant: 8.0),
            tableView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor, constant: -8.0),

            btn.centerXAnchor.constraint(equalTo: self.view.centerXAnchor),
            btn.topAnchor.constraint(equalTo: tableView.bottomAnchor, constant: 12.0),
            btn.bottomAnchor.constraint(equalTo: self.view.bottomAnchor, constant: -12.0),
            
        ])
        
        tableView.register(AnswerCell.self, forCellReuseIdentifier: AnswerCell.identifier)
        tableView.dataSource = self
        tableView.delegate = self
        tableView.isScrollEnabled = false
        
        titleLabel.text = "Sample Title"
    }
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return theAnswers.count
    }
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let c = tableView.dequeueReusableCell(withIdentifier: AnswerCell.identifier, for: indexPath) as! AnswerCell
        c.theData = theAnswers[indexPath.row]
        return c
    }
}

You can create a new project, copy/paste all of the above, and set the Initial View Controller to TheParentVC -- should run as-is.

If it works as desired, compare the constraints setup to what you're doing and see if you can find the difference(s).