Hi. Sometimes my browsers (Opera, Brave) open in a new desktop even after I moved it to desktop 1 and deleted others. Once Brave added 5 desktops in a row. I didn’t find how to disable VDs in KDE settings even if it was available few years ago.
System Settings → Workspace Behavior → Virtual Desktops
Delete all except VD 1
It has been done multiple times, no result.
nano ~/.config/kwinrc
Look for the [Desktops] section in the file.
Add or modify the following line to block the creation of new virtual desktops:
UserCreated=false
Looks like it didn’t help.