When all your notifications are read, the notification icons at the top of the page are supposed to be 50% opacity.
This works fine in Vector 2010:
However in Vector 2022 they are full opacity to begin with...
...until you click on them to open the dropdown, at which point they get replaced with OOUI versions and take on the correct opacity:
Update:
The decided fix is to never use 50% opacity as that looks like a disabled button, which they aren't.








