DisplayLink, Ubuntu 20+ and D6000 issues

Hi all, 
I can not use the Dock Station D6000 under Ubuntu 20+ and I can't figure why.

When I follow the instructions of DisplayLink of installation they say :

Error ! DKMS tree already contains: evdi-1.7.0.
You cannot add the same module/version combo more than once.

I tried every possibilities with purging or not DKMS packages but the result is the same error.

I can't figure out what is the problem as I am not an expert of Ubuntu but is there a possibility that the compatibility between Ubuntu and the Dock Station D600 has some issues ?

Thanks for your reply.

Adrien