An error occurred while saving the commentNicolas B commented
I have the same issue.
It started on a clean Ubuntu 18.04 install and remained all the way through 18.10, 19.04 and 19.10. My coworkers with mostly the same setup also experience it: 4 identical Thinkpad T580 laptops (Intel Corporation UHD Graphics 620) with Nnvidia GeForce MX150, with the same docking stations, displays, OSes and drivers.
In the 18.x versions, it was pretty random but would usually be fixed by rebooting (not always though).
In 19.10, it happens almost every time I plug the USB-C docking station with two additional 1920x1080 displays *AFTER* Ubuntu was already started (or starting). However it never happens if the docking station was already connected during the Grub phase (so rebooting fixes the issue for me). The bug also occurs if boot my computer with the docker station already connected, then unplug it, and then plug it back on.