SUMMARY

If you set your system to restore the previous session at startup, then discover does not respect it. Once you have used discover once, at every start up the discover window covers your desktop, even if you close it before shutdown.

I realize that I see the issue with an older version of discover. However this is what I get in ubuntu 20.04 since ubuntu has stopped providing updates to KDE via dedicated PPAS. Even if my version is too old for looking into it, I would appreciate any hint at whether this has already been fixed and a pointer, so maybe ubuntu can at least backport the fix.

STEPS TO REPRODUCE

1. Set your system settings > Startup and shutdown -> desktop session to restore the previous session at startup.
 
2. Open the discover software center
 
3. Close the discover software center

4. Logout

5. Login again 


OBSERVED RESULT

the discover software center is automatically started at login, producing a window covering the desktop

EXPECTED RESULT

the discover software center should only be started to open its window if it was open before logout, since the system is set to restore the session as it was before logout.

SOFTWARE/OS VERSIONS

Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 5.18.5
KDE Frameworks Version: 5.68.0
Qt Version: 5.12.8