I’ve noticed that, for example, WhatsApp calls and calls via my Bluetooth headset work without any problems. It really only affects the earpiece on my FP4.
I struggle with the same problem and am happy a new ticket was opened up. The way it is for me, I can often not take a call if I’m outside or in a cafe, orreally any place where someone else is talking. It’s unfortunately not a sustainable situation I think and might make me look for solutions in other ROMs eventually. Is there any reason to believe this works better in Lineage?