I have installed Kubuntu 22.04 and the latest OpenLP RC via:
sudo apt install openlp_2.9.5-1_all.deb
After doing system update via apt-get dist-upgrade and update of all pip packages I got a number of issues I will list now and give hints to solve these issues :-)
a) OpenLP starts successfully but Screeen cannot be changed and nothing will be rendered (preview or live). Additionally there seems to be an invisible layer with selected screen size at primary display. As a result no mouse clicks are possible anymore, but keyboard shortcuts are still possible
Finally I figured out that a newer version of PyQt were installed.
pip3 uninstall PyQt5 PyQt5-Qt5 PyQt5-sip PyQtWebEngine PyQtWebEngine-Qt5
pip3 install PyQt5==5.15.6 PyQt5-sip==12.9.1 PyQtWebEngine==5.15.5
b) with Fullscreen settings a video is flickering.
Fix: change taskbar setting to "Auto Hide" instead of stay on top