Microphone makes only a crackling noise in the beginning when recording

Hey everybody,
I’m also glad that I am not the only one. But I have some more thoughts about it:
Today, my bottom mic suddenly didn’t work anymore. I assumed it had something to do with the fact I exchanged it a few weeks ago because my old one had a connection problem.
I then put the old bottom module back in, hoping that the problem would be solved (the old one was ok but not more).
But in fact nothing changed, apart from the fact that now my upper microphone also isn’t working anymore. It did before.
That makes me think that it might have something to do with the fact I opened the FP several times today. Some screws are old so I didn’t want to tight them too hard.
Does anyone know, if there is a possibility to properly replace the screws? And is there maybe on specific of the 13 screws which is “responsible” for the sound connections?
Also I think it might be possible that the old problem was in fact a hardware problem, which was solved by replacing the bottom module, and that i created a new problem (which is even worse😭)
Thank you in advance, I’m really frustrated at this point and I really don’t want to buy a new phone…