Begging for some help with my BenQ XL2430T

[Erecshyrinol]

This is not an issue with the monitor, it's completely normal.

It's a combination of two factors. The swimming grain effect is called FRC and as Sparky said, it's most apparent with gray colors. On top of that, you have the relatively grainy coating, so you're seeing two layers of grain. It's very annoying, I agree. But also completely normal.

I could swear FRC artifacts were less visible on the LG 24GM77 (same panel, same coating), but I had that monitor for only a brief period and I can't compare side by side.