This looks like the problem, assuming the right section of the system log is attached in comment #1:
[36178.231698] Dapple gnome-shell[3998]: == Stack trace for context 0x5562d03ed170 == [36178.231698] Dapple gnome-shell[3998]: #0 5562ed968248 i resource:///org/gnome/shell/ui/windowManager.js:1542 (339f27529c90 @ 23) [36178.231698] Dapple gnome-shell[3998]: #1 7ffd1afab520 b self-hosted:1181 (3ed1fbfb0a10 @ 454) [36178.231698] Dapple gnome-shell[3998]: #2 5562ed9681c8 i resource:///org/gnome/shell/ui/main.js:260 (3ed1fbfef150 @ 12) [36178.231698] Dapple gnome-shell[3998]: GNOME Shell crashed with signal 11 [36178.231698] Dapple gnome-shell[3998]: == Stack trace for context 0x5562d03ed170 == [36178.231698] Dapple gnome-shell[3998]: #0 5562ed9681c8 i resource:///org/gnome/shell/ui/main.js:260 (3ed1fbfef150 @ 12) [36178.232108] Dapple gnome-shell[3998]: JS ERROR: TypeError: window is null _destroyWindow@resource:///org/gnome/shell/ui/windowManager.js:1543:9 _initializeUI/<@resource:///org/gnome/shell/ui/main.js:260:16 -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1969266 Title: application windows frozen after screen blanking To manage notifications about this bug go to: https://bugs.launchpad.net/gnome-shell/+bug/1969266/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs