ubuntu 20.04 and multiple screens
 

Hi,
I installed the latest drivers from the website without issues. Good work!
I have 2 screens attached to the Thinkpad Hybrid USB A and USB C dock, working with a new Dell XPS 13 2-in1.

However, I now run into the following issues;
- When the dock is connected, Ubuntu won't boot. Removing it boots just fine.
- When I disable the laptop screen from display settings, there is a lot of lag in the system when using it. Typing shows on the screens with a huge delay. Starting apps is slow (but I believe it is showing them started that is slow, not starting the app itself).
- When I run the system with 3 screens (i.e. both external monitors and the internal one) switched on, it runs as smooth as without the external screen.

on 18.04 (elementary) and 19.10, running with the internal screen wasn't needed for acceptable performance.

What can I do to get to my preferred setup?

thanks