I am running KDE with Ubuntu 20.04 on a Dell Latitude 5500 with two Dell U2412M monitors connected via a D6000 dock. For the most part, this setup works well.
The laptop screen is on the left and the two monitors are extended to the right.
In a Google Chrome browser on the middle screen, I was having some difficulty clicking in the scroll bar on the right side of the browser. When I tried to mouse into the scroll bar, the cursor jumped from the middle screen to the right edge of the right screen.
I replaced the connection for the right hand screen with an HDMI connection and the issue disappeared.
Unfortunately, I cannot upload the output from DLSupportTool, with NGINX reporting:
413 Request Entity Too Large