Don’t know when you last tried this but definitely not a download a deb and double click situation

Nope. Installed ubuntu to test. Am usually an Arch user. Currently have Fedora KDE installed.

Can’t you set fullscreen in the options?

There was an issue after update the other day and others had already posted. Use search function in future. I was able to launch this morning.

Make a group and add both users to the group. Then change ownership to your user and that group.