@brnmatrix should be the same way updating these json files:
C:\Users\username\AppData\Roaming\Opera Software\Opera Stable\Preferences C:\Users\username\AppData\Roaming\Opera Software\Opera Stable\Preferences.backupI didn't find that bug on Windows, but have another one:
Undock DevTools Dock it back Click on 3 dots button. Opera crashes & reopens.