I fear that while you have supplied some data, it is not enough for anyone to be able to help you.
To start, what base Devuan release you are using.
I would assume Daedalus (?), but that is just me assuming.
ie: the output of

~$ uname -a

Then, the brand/model of the docking station would be one very important bit.
Also, if you are using the PS/cables supplied for the docking station or are using a different PS or other non-OEM cables; it can be a problem if the cables are not the excat spec the docking station requires.

Then comes the proof of life, so to speak:
The [dmesg] printout with the docking station and monitors in place and powered on.
That would give us an idea of what is going on with the docking station / monitors as your Thinkpad boots.

BTW: please make sure you use the proper [tags] when posting the dmesg output. 
eg:

--- snip ---
01:00.0 VGA compatible controller: NVIDIA Corporation TU106GLM [Quadro RTX 3000 Mobile / Max-Q] (rev a1)
00:02.0 VGA compatible controller: Intel Corporation CoffeeLake-H GT2 [UHD Graphics 630] (rev 02)
--- snip ---

Something you may want to consider trying (to rule out any Artix Plasma issues) is to boot a Devuan Live *.iso and see how it goes.

Best,

A.

There are 2 graphics cards:
01:00.0 VGA compatible controller: NVIDIA Corporation TU106GLM [Quadro RTX 3000 Mobile / Max-Q] (rev a1)
00:02.0 VGA compatible controller: Intel Corporation CoffeeLake-H GT2 [UHD Graphics 630] (rev 02)

Perhaps the incorrect video driver?
Unfortunately, the two external monitors connected to the Thunderbolt are not working.
They are visible in the control panel, but there is no image. The Thunderbolt is activated, and the keyboard, mouse, and network are working.

Can you help me solve this?
Thank you.

rrbs