OK, thanks. I forgot something...
Now that you only have Ubuntu extensions installed please start disabling those via the Extensions app. Log out and in again afterwards to be sure.
Then when you're using gnome-shell without any extensions does the bug still occur? If so then please run:
gsettings list-recursively org.gnome.shell > shellsettings40.txt
and attach the resulting text file here.
OK, thanks. I forgot something...
Now that you only have Ubuntu extensions installed please start disabling those via the Extensions app. Log out and in again afterwards to be sure.
Then when you're using gnome-shell without any extensions does the bug still occur? If so then please run:
gsettings list-recursively org.gnome.shell > shellsettings40.txt
and attach the resulting text file here.