TabControl - Shadow drops behind Card in TabItem #2667

First of all, thanks for creating an amazing toolkit!

When using the TabControl with for example materialDesign:ShadowAssist.ShadowDepth="Depth2" and in the TabControl a TabItem that contains a ScrollViewer and materialDesign:Cards, the card will appear in front of the TabControl header shadow when scrolling (tested with v.4.4.0 and v4.5.0).

When only using a Toolbar ColorZone, without a TabControl, the same shadow issue will occur. This however can easily be fixed by adding Panel.ZIndex="1" to the Toolbar ColorZone and Panel.ZIndex="0" to the content ScrollViewer. This was discussed in issue 647.

When using a TabControl, setting a Panel.Zindex on the TabControl, TabItem, and/or TabItem Content will not fix this issue. Perhaps this issue can be fixed by setting the right Panel.ZIndex on the TabItem Header and Content in the TabControl Style in MaterialDesignTheme.TabControl.xaml.

TabControl with shadow that appears behind cards

Kind regards and all the best,
Arjan