We've had that happen, and, from your pics, I agree it looks like bleed-thru from something.

Either bleed through (colour coming up from underneath) or it is being removed because painters tape (tape removal can rip off paint from the surface) OR it is someone's dirty clothes/cloth/plastic that has deposited gray(ish) paint onto the surface of your wall. The pattern looks like something dirty (with wet paint) was up against your paint (wet paint on overalls, wet paint on plastic sheeting, wet paint on cloth sheet, etc).

To me it looks more like a "deposit" rather than bleed through.

Thank you all for your tips- we are first time home buyers and our builder has been terrible. Do you know how bleed through should be fixed?