If you're using Plasma/KWin 6 i suggest you disable the Morphing Popups effect, it has been removed for Plasma 6.2 https://invent.kde.org/plasma/kwin/-/commit/d6360cc4ce4e0d85862a4bb077b8b3dc55cd74a7 and on X11 at least it causes severe redraw issues with tooltips in Okular (and i would guess elsewhere).