David,
If you refer to the Plex Media Server installation update issues thread, you’ll find that there is a condition where PMS is legitimately configured without being owned by username plex. That condition has been reduced to a Warning.
In the above text message from Preinstallation verification, it’s telling you it didn’t find any trace of ownership change from user plex to myuser.
I am interested in understanding your configuration and what it is misunderstanding about your configuration. It should have found and digested your systemd override.conf file.
Can you share a bit about how you have PMS configured?
