Macbook Pro + 4K monitor mouse lag

[Stephanbar]

Hi, I am using following setup

- Macbook Pro 16 inch (2019)
- belkin thunderbolt 3 dock plus dockingstation
- iiyama XUB2792UHSU-B1 4K Monitor

As I connect those with a display port cable, the mouse is suddenly really laggy, which makes it really hard to work focused.

Does someone know what I have to adjust to make the mouse go smooth?

Thx in beforehand!

 

[grahamvinyl]

Did you ever find a solution to this?