Not a regression as I was able to repro this in 4.25.4
The bug doesn't occur every single time, you may need to try disabling/re-enabling the setting and/or clicking on the menu dropdowns a few times. It happens more often that not though.
Result: Dropdown menu flickers and is unclickable
Expected: Dropdown menu looks and functions normally
There's no existing public thread on this issue, so head over to AnswerHub just mention UE-105239 in the post.