Looks like it needs Qt fixes relating to how geometry updates work on Wayland. KDE will be able to proceed in fixing the issue after this one is fixed on Qt’s side: https://bugreports.qt.io/browse/QTBUG-126746
There is a lot of KDE bug reports marked as duplicates of the bug reported in @filo’s KDE bug link; so it is effecting a large amount of users I would bet. I don’t use a separate panel for just my icons-only task manger , so that might explain why I haven’t noticed this bug. There might be other workarounds for the issue as well.