Video has no audio, iPhone 14 Pro

So I recently went to a concert and I was recording multiple videos. There was a part of the concert where I was able to take a video but my phone was not able to record an audio. Is this a glitch or bug? My other videos have an audio but there are like 5 videos that do not have an audio. I was also only able to check the audio after the concert ended.

Is there also a way to recover the video with an audio? I really hope this is just a bug where I can still recover the video’s audio.

I also checked my videos with my phone unmute and on full volume. There were like a maximum of 7 videos with no audio while the rest have audio.

Any help will do. Thank you!