SUMMARY
I have a Firefox browser window with many tabs that I have open all the time. In order to avoid having to manually open the browser every time I turn my PC on, I have Session Restore configured to open it for me automatically when I log into KDE. At one point there was an empty Firefox window open when I shut off my PC. Now that window opens continuously even after I close it. I have tried setting Session Restore to manually saved sessions, closing the empty browser window and manually saving the session but it does not prevent the window from opening. 

Previously I had a similar issue with psensor which would open every time I had Session Restore on. I turned Session Restore off for several months in the hopes it would go away, but when I re-enabled Session Restore, psensor would again continue to open. This did stop after I switched to manually saved sessions and saved a session without psensor open, however the browser issue previously described persists.

STEPS TO REPRODUCE
1. Enable Session Restore
2. Open several windows and log out of the KDE session.
3. Log back into the KDE session and allow the session to restore.
4. Close a few of the windows and log back out of the session.
5. Log back into the session and observe that Session Restore proceeds to reopen all of the previously closed windows.

OBSERVED RESULT
Empty browser window that was no open when KDE session was manually saved still opens on login.

EXPECTED RESULT
Windows not open when the session is manually saved or when the session is ended when manually saving is disabled, should not open.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: EndeavourOS rolling release with whatever the latest KDE is.
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION
I have a log from journalctl here: https://pastebin.com/QWhYbfi5