Hi, I managed to get the second screen to work, by adding intel_iommu=off to GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub/.
But it's pretty unstable: disconnect the cable, open a window, and the gui system restarts -- the system doesn't crash completely, though. I haven't been able to get much out of journalctl yet ; I will try to get more information on the matter. In the meantime, there's already something clear to improve the situation: make the kernel detect intel_iommu should be disabled in certain conditions. Cheers, J.Puydt
