Hello, I have a single left screen rotated 90°. When I apply it, kde is not usable anymore. The mouse clicks and the pointer are not in sync. Besides that, most of screen content is garbage.
It is not yet possible to rotate screens on Wayland. We even point out to it in the known issue section that screen configuration is not yet fully implemented. This is not yet part of our feature set. Thus I mark it as invalid (it is not a bug from our perspective). We track the development of new features through https://phabricator.kde.org/project/view/99/