Strange snow effect on monitor

[Jonnibravo]

My son has a gaming setup specs below, he's just bought himself a gaming/smart monitor Samsung Odyssey g6 240hz

Ryzen 5 2600
3060ti
MSI B450 vdh pro

A strange thing is happening though it's barely noticeable unless you know it's there which he does, like small dots almost like snow trickling down the screen in a line about 1cm width, this appears to happen every few minutes. I have had the monitor on my pc and it does not happen, any ideas what this could be. He's tried different cables, hdmi and display port so I'm confident it's not the monitor. The odd thing is it didn't happen on his lg gk32 650f 144hz monitor.

 

[Jonnibravo]

That's what I thought the refresh rate, thanks for the advice guys I'll try them and post back of there's any success

 

[Jonnibravo]

have you figured out how to fix it? i have the same issue :/

Sorry I took so long, No we believe it may be the motherboard, it's pretty basic(cheap), so I think its the combination of high end GPU and CPU coupled with the PSU and MB being pretty basic. I put the monitor on my setup for a day and it seemed to work fine, whats your setup?? Could you confirm any of what I have said.