Our Apple TV provides UIImages with renderingMode forced to .alwaysTemplate (the images are also configured with "Render As" to "Template image" in the Asset catalog) to UIActions as UIMenuElement when building a UICollectionView UIContextMenuConfiguration.
Problem: these images are not displayed with vibrancy effect by the system. The issue does not occur with system images (SVG from SF Catalog).
Here is a screenshot showing the issue with custom images ("Trailer" and "Remove from favourites"):
I don't know the underlying implementation of the context menu items image but UIImageView already implements the tintColorDidChange() method and the vibrancy should work if the UIImage is rendered as template.
According to my tests, the vibrancy is correctly applied when using Symbols sets instead of Images sets but I understand that custom images rendered as template should support it as-well, shouldn't they?