iPhone X mic not working

Hi! So my issue is that my iPhone X mic doesn’t work properly. If I use Instagram, Messenger or any app, both front and read mics work as they should. However if I use the Camera app, only the front video has normal sound. The videos recorded by the rear cameras only have a hissing sound.

I tried resetting the phone completely, but it didn’t help. Also it cannot be a hardware issue (I think) because the microphone works in other apps.