Apologies for the delayed reply. I've done some additional testing, including the Wayland session. Here my findings:
removed .config/monitors.xml and .config/monitors.xml~ unplugged monitor cable, unplugged monitor power shutdown > start-up Set display preferences for single/laptop screen shutdown > start-up plugged in monitor power plugged in monitor to laptop - no change - opened display settings monitor starts up as second screen changed settings as needed for both screens > apply > keep settings second monitor switches off shutdown and restart > second monitor on and with correct settings lock screen > wait for second monitor to go back to sleep -- correct behaviour resumes -- wake screen > both monitors resume as expected suspend machine > resume > both monitors resume as expected -- END-- unplug second monitor > single/laptop display resumes correctly plug second monitor back in, display remains unchanged (laptop/single only) unplug second monitor suspend laptop plug in second monitor resume laptop, second monitor remains off logout login screen displayed with second screen now enabled login display resets to multiple display desktop but second screen remains off remove second screen > display resets correctly to single laptop screen shutdown --- correct behaviour resumes -- plugin in second monitor start both screens active including login login both screens working as expected lock screen > all screens suspend move mouse to active screens > both resume and can login suspend suspend machine > resume > both monitors resume as expected suspend > unplug second monitor > resume > single display/laptop works as expected -- END -- suspend > plugin in second monitor > resume > display remains in "single" mode > second monitor remains off restart gnome-shell (Alt+F2 > r) display resets to correct two display setup with second monitor on lock screen > monitor suspend > move mouse to activate screens > only laptop screen wakes up shutdown --- correct behaviour resumes -- start both screens active including login login both screens working as expected lock screen > all screens suspend move mouse to active screens > both resume and can login suspend suspend machine > resume > both monitors resume as expected END TESTING Wayland --------- setup second display, all working as expected (lock screen and suspend resume work fine) remove second screen > screen resets to single display plug in second screen > no change open display settings > display settings do not recognise second screen logout login screen, both displays work login > both displays working as expected (lock screen and suspend resume work fine) suspend > remove second display > resume single display resets as expected suspend > add second screen > resume second screen remains off, display remains in 'single' display mode. logout login screen, both displays work login > both displays working as expected (lock screen and suspend resume work fine) END WAYLAND TESTING Thanks for the time and effort all. -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/1886672 Title: Second screen is not always made to awaken when using multiple displays. Desktop is multiple display, but only laptop screen is on while second screen sometimes remains off To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1886672/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
