I'm guessing the dock uses DisplayLink, in which case the compositor needs to have implemented special support for that (like mutter/gnome- shell already has). To confirm this theory, please tell us the model of dock as well as running:
lsmod > lsmod.txt journalctl -b0 > journal.txt and attach the resulting text files here. ** Package changed: wayland (Ubuntu) => plasma-workspace (Ubuntu) ** Summary changed: - Wayland does not detect external monitor + KDE Plasma Wayland session does not detect external monitor ** Also affects: kwin (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1964126 Title: KDE Plasma Wayland session does not detect external monitor To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/kwin/+bug/1964126/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs