Looks like a difference of 11ms, so less than one frame. This is most likely to be a buggy app (or toolkit) as the message suggests. Please try to identify what the offending app is. For example if the window ID is still 0xa0000e then:
xwininfo -id 0xa0000e or xprop -id 0xa0000e | grep _NET_WM_PID ** Package changed: gnome-shell (Ubuntu) => ubuntu ** Changed in: ubuntu Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1973583 Title: gnome-shell[200033]: Window manager warning: last_user_time (394951544) is greater than comparison timestamp (394951533). This most likely represents a buggy client sending inaccurate timestamps in messages such as _NET_ACTIVE_WINDOW. Trying to work around... maj 16 10:33:15 graf gnome-shell[200033]: Window manager warning: 0xa0000e appears to be one of the offending windows with a timestamp of 394951544. Working around... To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/1973583/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs