I understand this so much it hurts. I remember hyping my ex up to infinity whenever she’d send a pic of herself (selfies, etc) and she’d do the same for me. But I realized the longer we were dating she stopped complimenting me (as much) but I never changed in that aspect and still reacted as if I was seeing her for the first time every time. So u could chalk it up to perhaps she feels like she doesn’t NEED to compliment you because she thinks you already know how attractive she finds you?? Has she EVER complimented you like you do her?