iPhone XR - Video has no sound?

I have an iPhone XR and whenever I record videos and watch them, they don’t have sound or rather the sound is very muffled and has almost no audio. I’ve adjusted the volume several times and even have restarted my phone multiple times as well. Recorded videos is the only place my sound doesn’t work (it works for playing music, voice memos, YouTube videos, etc.). I’ve taken off my case and cleaned out my microphone too but it still has not solved the issue? What else do I need to do?

(my software is up to date as well - iOS 13.3)