Switching the ports so that the WD15 dock is connected to the USB-C port closer to the power socket and the display is connected to the other USB-C port fixed the issue. Apple USB-C to HDMI dongle exhibited the same issue when plugged into the same port. When the WD15 was connected to the port closer to the power socket with a display attached, USB devices intermittently disconnected and reconnected. Likely a hardware defect, but @mapengyu could you try to reproduce with the ports switched around?
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1881213 Title: System hangs at reboot or poweroff. kworker blocked at dp_altmode_work To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1881213/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs