On Motorola Moto ONE Visión, Android 10, QSAS220.127.116.11:
My voice is barely audible to the ones i'm talking with, on WhatsApp and instagram videocalling. Checked for dust or anything blocking the microphone audio input, but all was right. I even tried to plug in an external mic (rode videomic), and my voice volume was still low for my interlocutor.
When I film a video on the built in camera app, there's no issues on audio recording. Same happens when sending WhatsApp and instagram audio messages, all goes well then.
I guess it must be something related to simultaneous audio outpu/input, or maybe mic noise reduction software, but I can't find where to adjust it.