I did some additional testing to see if this is thunderbolt in general or just the TB16. The issue does not occur when using external monitors via HDMI + thunderbolt-to-HDMI connections directly on the laptop. It looks like the issue is indeed specific to TB16.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1752165 Title: TB16 dock freezes X on hotplug when used with external displays To manage notifications about this bug go to: https://bugs.launchpad.net/dell-sputnik/+bug/1752165/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs