Solved
[Android] Definition popup showing next kanji for one frame
Doesn't happen on iOS, didn't happen prior to 0.20 update to iOS. wtf!?
If I'm understanding this correctly, this is happening for me on iOS. When I press next (➡️) on the bottom bar during reviews, frequently (I can't say exactly how often though because I try to avoid looking) the definition (including the text render of the Kanji) will be visible very briefly. It looks like the label at the bottom is being updated before being hidden or something.
Added a new ticket for this here:
https://ringotan.helprace.com/i495-ios-definition-popup-showing-next-kanji-for-one-frame