Saturation changes with mouse movement

Hi,

I got a new machine – a Mac Studio M3 Ultra.
When I move the cursor (over the artboard or outside of it), the colors change — they become either more saturated or less saturated. I can’t find any logic behind what causes the shift.

I thought it might be related to the low refresh rate of the monitor (Apple Studio Display 27"), but this only happens while working in Illustrator. Everything looks fine in Photoshop and After Effects.