In the FWIW category: I've had this problem for decades, prior to getting on TRT, which is my only use of AAS. When I got on TRT, we found that my E2 levels were off the chart high, so one of the meds I take is Arimidex.
After experimenting with taking this drug, and not taking this drug, it really seems like when I'm good with taking it consistently, the acne on my scalp is pretty much gone. If I skip taking it for a week or two, boom, the acne is back.
I even ended up shaving my head completely, hoping that would help control this acne, and it didn't. All that accomplished was putting the acne in clear view.
So maybe get your E2 levels checked? Maybe you need to get on an aromotase inhibitor?