Interesting issue. …
On FP4, my audio is fine when recording Signal audio messages and video message. However, if I do a Signal video call, the opposite side can barely hear me (and hears her echo louder than my voice). She had a Samsung phone and always just called me back. If she initiated the call, she could hear me fine.
Now she bought a Fairphone as well … so now, if she calls me, she can hear me fine but she is very quiet for me. If I call her, I can hear her fine but I am quiet for her.
I am using the FP4 with iodeOS (LineageOS fork, I think); she is using FP5 with unchanged FairphoneOS.
Not sure how to proceed from here. 