Visual Studio Extensibility: Rectange-s added to Children class of the ScrollbarMargin prevent mouse clicks on the scrollbar

I've developed an extension some time ago that allows to highlight a section of the scrollbar with the specified color, here is how I do it:

/// <summary>On layout changed analyze the regions and lines and highlight them on the scroll bar if needed.</summary>
    private void OnLayoutChanged(object sender, TextViewLayoutChangedEventArgs e)
    {
        Children.Clear();

        int n = AllAdornments.TextAdornment.Regions.Length;
        for (int i = 0; i < n; i++)
        {
            if (AllAdornments.TextAdornment.Regions[i].Adornment != null
                && AllAdornments.TextAdornment.Regions[i].EndLine < e.NewSnapshot.LineCount)
            {
                var rect = new Rectangle();
                var firstLine = e.NewSnapshot.GetLineFromLineNumber(AllAdornments.TextAdornment.Regions[i].StartLine);
                var lastLine = e.NewSnapshot.GetLineFromLineNumber(AllAdornments.TextAdornment.Regions[i].EndLine);
                double top, bottom;
                double firstLineTop;
                MapLineToPixels(firstLine, out firstLineTop, out bottom);
                SetTop(rect, firstLineTop);
                SetLeft(rect, ScrollBarLeftPadding);
                MapLineToPixels(lastLine, out top, out bottom);
                rect.Height = bottom - firstLineTop;
                rect.Width = ScrollBarWidth;
                Color color = Communicator.LerpColor(AllAdornments.TextAdornment.UserBackgroundCol,
                    AllAdornments.TextAdornment.Regions[i].Adornment.Color, ScrollBarIntensity
                    * AllAdornments.TextAdornment.Regions[i].Adornment.IntensityMult);
                color.A = ScrollBarOpacity;
                rect.Fill = new SolidColorBrush(color);

                Children.Add(rect);
            }
        }
   }

Here is how it looks in Visual Studio:

This worked perfectly for a long time (around 1,5 - 2 years), but when I updated VS four months ago a problem emerged: I can no longer click on the section of the scrollbar margin with the colored Rectangle - the mouse click simply does nothing as long as it is above the colored Rectangle. On the empty section of the scrollbar it works as usual. Before I could not only click on my Rectangle-s, but hold the mouse button down and drag the scrollbar. Is there any way I can bring back this functionality?

Can you try setting rect.IsHitTestVisible = false;