I’ve discovered a bug using Plasma / Wayland / Libreoffice, where clicking simple dialog popups such as the font size or the font color result in failure to display the dialog. Or more correctly I can sometimes see the color chooser flash briefly in middle of screen. Therefore cannot choose color.
Under X11 there is no problem.
As I am uncertain where the bug actually lies (LO or Plasma ?) I have not yet reported anywhere.
A further possible issue is NVIDIA graphics affecting Plasma in Wayland. All the same, the KDE developers may appreciate your filing a bug report even if it turns out that it isn’t a Plasma issue, per se.
Hmmm just realised something has stuffed up the Global Menu by doing this too; it doesn’t appear at all in Libreoffice now, but used to. No reversion nor other options is bringing it back. Busy trying to hunt down what arcane file controls that.
The fix for menus not appearing with LO is to go into KDE system settings, Background services, turn off the Application Menus Daemon, Log out, back in.