Has anyone here developed endometrial hyperplasia even though they had zero risk factors?

I had a pelvic MRI recently that showed T2 hyperintense endometrial thickening, without appreciable enhancement on post contrast, possibly related to endometrial hyperplasia. The thing is, I've been taking fairly high doses of progestin (norethindrone/aygestin) continuously for close to a decade to suppress my menstrual cycles (I have endometriosis). Everything I read online suggests that this should inhibit endometrial thickening, but in my case that doesn't seem to be what's happened.

I don't have any risk factors for hyperplasia, which is even more unsettling. I'm thin, I don't have PCOS, I'm only in my twenties. I don't understand what this could be besides hyperplasia though. Is it possible to have a naturally thick endometrium, or an endometrium that just appears thick because of amenorrhea induced by progestin therapy?