Samsung monitor suddenly a white box?

I recently got an https://www.mediamarkt.de/...25889.html

Bought monitor that ran super for the first few minutes. Then I wanted to go through the settings and set a lot e.g.

FreeSync on, which then caused problems and then when I turned it off I noticed a white box on the screen, cables changed, problem still there, restart monitor, restart laptop, problem still there

Resetting the monitor didn't work either

Have a 10 on a laptop and connected via HDMI to the monitor

Edit: when I drive the PC up and down everything is normal at the point, so the monitor is already intact?

Could be due to the graka, but unfortunately I don't know exactly what it is