I am seeing this in 19.10 (POP_OS). Nvidia 1060. Mutter is indeed at 3.34. Basically any time I alt-tab or otherwise switch between windows it freezes and I get this syslog message.
-- 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/1825626 Title: nvLock: client timed out, taking the lock To manage notifications about this bug go to: https://bugs.launchpad.net/gnome-desktop/+bug/1825626/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs