I’ve just updated this morning my FP3 to /e/OS 0.18-20210813129945 which I received via OTA.
Not sure it’s the right place for that, but if needed I can create a new thread.
All was running just fine with last /e/OS 17 branch version installed.
All went well after upgrade, until I received a phone call. I was not able to hear the person as I was not able to use the mic as well. 
Originally I thought that it was coming from the MIC driver itself or so…
When I use signal app for phone call I have the same issue.
But I can record my voice and send it to signal as a message.
I’ve tried with a bluetouth headset and no luck as well, I can hear the person but no sound is received by the person.
So I suspect an issue at the sound manager itself and not driver level, since I can listen some sounds and record sounds in some conditions.
I’ve tried to reboot, but no improvement. My phone is fully charged.
Any idea what I can do to get that fixed ?
As you can understand, as the basic function of a phone is broken, I will not be able to stay in this situation. So if some logs needs to be collected let me know very soon.
I plan to do a factory reset maybe tomorrow or the day after to give a try, but I’m very reluctant to do that as I will have to reinstall evry thing 