Had AirPods Pro's for about 2 month and all working great. Then bass response dropped, then fit test kept failing. Apple replaced the pods only. Then that set started crackling. Replaced again. Then more problems with next 2 sets. I am now on my FIFTH set. Bass response excellent, fit test reports a good seal, but ANC is virtually non existent. This is a set that was delivered just over a week ago. So I can only assume under the program they are now replacing broken AirPods with broken AirPods? In addition to this, with this pair, switching between my iPhone and Mac just doesn't work. Could this be hardware also? My last pair worked OK. They were on old firmware when they arrived but they have now updated. Same issue.