Does not appear to be fixed in iOS 26 RC. Looks like iOS 26 is shipping without it, which is wild, considering that is was core functionality the WWDC videos described exactly how to use.

I similarly still can't get this to work, as of Beta 7.

Ziqiao, I was placing it in a UIVisualEffectView with vibrancy because in beta 4, if my symbol was a standalone UIImageView in the custom view, it didn’t get the default effect. I think this was one of the same beta 4 bugs that @KeithB was seeing. But now 

I can tell you that in beta 5, a UIImageView alone in the custom view finally behaves appropriately. It because unnecessary to embed it in the additional UIVisualEffectView with vibrancy and just put it in the custom view alone as you suggested, @DTS Engineer. Thanks.