I have a strange issue specifically with Firefox running on plasma wayland. Whenever I try to save a bookmark by dragging and dropping the window bar into a nested (at least 1 level deep) bookmark folder, the drop highlights are firstly incorrect and second, don’t open the 2nd level folder I want to get into (in the video I’m trying to go into Links → KDE → New Folder. This is the only application where I’ve seen such issues, sometimes, right click menu for a bookmark is about 200px off to another side etc.
Looks like I can’t upload video here (webm from spectacle), so I’m linking to a pastebin service (hope that’s acceptable) - https://0x0.st/8SWh.webm