This is a virtual install.
A Snap Plex install in Ubuntu sets the proper folder and file permissions, while a .deb downloaded install from Plex doesn’t.
If you follow Plex’s official install instructions found here for Linux…
https://support.plex.tv/articles/2002...
You will need to sort out permissions with the help of this article.
https://support.plex.tv/articles/2002...
Use the Snap install from Ubuntu’s Software store to avoid learning about Linux permissions.
Plex's main support document listing... https://support.plex.tv/articles/
Plex's Remote access guide... https://support.plex.tv/articles/2002...
Plex's main movie naiming guide... https://support.plex.tv/articles/nami...
Plex's series naming guide... https://support.plex.tv/articles/nami...
My remote access tutorial... • Plex Remote Access via Port Forwarding
My detailed movie naming guide... • Modern Plex folder and filenames versus ol...
My detailed TV series naming guide... • Helping Diego with Plex TV Show naming rul...
Plex Scheduled Tasks, using the Plex Dance sequence, and series that have different listings at TMDB & TVDB... • Plex Sceduled Tasks, Plex Dance, and issue...