ThinkPad W520 screen flickers when attaching Duex

[Bashar]

Hi all,
I have noticed that Ubuntu official driver is available so I wanted to use it on my laptop

I have successfully installed the drive and the Duex is working just fine

But I noticed something weird on laptop main screen, while moving the mouse on screen a small square starts to flicker randomly below the cursor

Anyone noticed this before and managed to solve it?

Thank you

Some Tech specs if it helps:
I have Nvidia Quadro 2000M card and running ubuntu 18.04.4
I also have Intel built-in card which I have it disabled to be able to drive multiple screens at office when I dock the laptop

P.S: I tested the Duex on thinkpad X1 Yoga and windows last night and didn't face this isse