My PS4 headset, when plugged into the PC, will only pick up audio from the "earmuff"/"over-the-ear" part of the headset. Anyone know why?

In other words, when I wear the headset as intended, sealed over my ears, people can barely hear me...but if I take them off and speak into the "earmuff" part, I'm crystal clear. This does not happen on the PS4..I can use them with the PS4 with no problem at all..

Probably notable (but i dont understand why), I am connecting to the PC through aux to the mic input on the PC while I connect to the PS4 through bluetooth. I tried connecting through bluetooth and I couldn't get the mic to work at all.