why UITableViewAutomaticDimension not working?

Hi there is plenty of question answering the dynamic height for UITableViewCell of UITableView. However I find it weird when I did it.

here's are some of the answer :

here and here

usually this would answer the dynamic height for cell

tableView.estimatedRowHeight = 44.0
tableView.rowHeight = UITableView.automaticDimension

but in my case I wonder this line wont do anything.

my UITableView is being viewed after clicking tabbar inside the splitview. Is this helpful?

Maybe I'm Missing something. Could anyone help me I spent 2 hours doing silly.

These are my constraint for title the title could be long but the label is not.

and this is my cell

In order to make UITableViewAutomaticDimension work you have to set all left, right, bottom, and top constraints relative to cell container view. In your case you will need to add the missing bottom space to superview constraint for label under the title