OK, it's likely caused by mutter upgrade, but let's make sure that's the case. Can you please downgrade the mutter to verify the old version works?
Please run `sudo apt install libmutter-10-0=42.9-0ubuntu5 mutter- common=42.9-0ubuntu5 gir1.2-mutter-10=42.9-0ubuntu5` to downgrade related packages. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2060204 Title: Resolution drop on third monitor on USB C To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2060204/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs