I have issues with the microphone being crackly and then cutting out so people can’t hear me. Not all the time, but most of the time. Can temporarily help by going on to speaker but then it often cuts out completely - bit like it got fed up! It works on video recording but not video calling. Tried help but VERY slow and now can’t rely on phone for important calls.
You have three three microphones in total, this could explain the difference between camera use-cases and calls. Please dial *#*#2886#*#* and choose Audio. Skip the first tests with PASS if the phone plays a sound. More relevant to you are the test named mic x to xxx. Just blow at the little holes in these spots and check if you get a consistent sound played back.
Microphone 1: lower side, left
Microphone 2: upper side, right
Microphone 3: left side in the middle
No tips I’m afraid – just poor service. I had to return the original as it wouldn’t turn on, I think they replaced it with a renovated one and very soon had the microphone issues. I now have to send it to France for repair (amidst mail strikes) and it has been a massive hassle. Firstly, as I ad to source another phone – I replaced the last one for a reason!) then realised that as I have an esim I had to order another physical sim. Then I had issues changing back (not FP issues to be fair but the normal hassle of transferring phones) and so now have to summon the courage to post it! It takes so long to get answers that I am fed up with the process.
Last one (FP2) was abandoned due to on going screen issues so wondering why I do this to myself!