iPad is screen recording audio missing when uploading to YouTube or iMovie?

Hello, my son and I screen record games on his iPad and we upload those gaming videos to his YouTube channel. We recently screen recorded his gameplay and it turned out great. However, when I try to upload the video to YouTube directly, YouTube Studio, or use iMovie to try and edit it, the audio is missing. The audio is not missing in the iPad video library, though, as I can watch and listen to the video there. But when attempting to upload the video to YouTube or iMovie, the audio is missing. I always make sure the mic is turned on. Obviously since I can hear the videos audio when playing it in the iPads video library, there is actual audio with the recording. Does anyone have any advice? Thanks.

[Re-Titled by Moderator]

Original Title: iPad screen recording audio