Monitor has washed out blacks on M2 Air vs M3 MBP--and changes when you close the lid

I have an M3 MacBook Pro and an M2 BackBook Air. I have been using my LG 27UL500 as a second display with the MPB for weeks and it has nice, dark blacks. I plug the Air into it with the same displayport cable and the everything is washed out and the blacks are gray. You can see in this image I took with my phone. Zoom in and see that the settings are the same, the resolution is the same, the refresh rate is the same and the color profile is the same. But here's what's *even weirder*--when you close the lid of the MBP *the external display becomes washed out too*! What could cause that?