I have heard there can be a lag with Medium recording read times, I don't know if it's true but I have had a few instances of zero read time from people I always thought read me. Those big Facebook groups never seemed to generate real interaction to me, maybe start your own with some writers you enjoy interacting with. I feel bad for people who ask for reads on the one hand because I know it's not easy to get reads but you are right, they rarely if ever read you back lol! Some people really don't get that being genuinely interactive on here is (or was) the only only to gain traction.