I am using a Lenovo ThinkPad X1 Extreme Gen 3, with fully updated Kubuntu 20.10, with KDE plasma 5.19.5 and trying to connect two external Samsung monitors using ThinkPad Thunderbolt 3 dock (gen 1). Both monitors have HDMI cables, I am using a displayport-HDMI adapter for both.
I could a couple of times get both the screens to work on this dock, but once I disconnect the dock and reconnect it, my system seems to forget whatever those settings were. Either one or both screens show up black, they exist are detected, show up in settings and I can drag windows there; but nothing really shows up for the human eye to see, not even the mouse pointer.
The second time it worked was when I switched off the NVidia card rebooted, switched to nvidia card and rebooted again, but same thing happened after disconnecting the dock.
When it works, I have to add a new panel, and widgets again. It shows blank, but I can at least see my mouse pointer; in this case, basically that screen has no widgets/wallpaper. I can add these; but when it doesn't even the mouse pointer does not show up.
I can see the two screens in the settings, re-arrange them; if the middle screen is not working I can drag a window all the way over to left screen through the void. Whether the monitors work or not other peripherals like keyboard, mouse etc seem to work through the dock.
I do not seem to have .config/monitors file; I tried removing .local/share/kscreens but it did not help; it just stopped detecting the monitors even in settings so I added it back.
The monitors work, machine is fine, can display 2 screens and all, cause it sometimes works and cause I have another dock, a DisplayLink enabled dock with which I can use both monitors.
How do I make it work on the thunderbolt dock?
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