I would like to report another KDE Plasma bug, this one concerns the hamburger menus:
The transparency effect doesn't work in the first level menu, but it works in the second level menu. I posted an example with Dolphin, but it also happens with Gwenview and Okular, wherever there is a hamburger menu. If I switch to Menu Bar, the problem disappears. I use the Breeze theme, by the way.
This bug is reported on the KDE site
I noticed this bug when updating to KDE Plasma 5.23.3. After checking eopkg history, it was when KDE Frameworks got updated to 5.88.0. I'm talking from memory, I could be wrong.
This bug doesn't affect functionality at all, it's just a question of aesthetics, so I suppose it's not prioritary.
Thank you in advance