Imovie Deleting Audio

[Detective Alex]

So I run a small gaming YouTube channel and I recorded an Among Us video on my iPhone 6s using the control center thing. I airdropped an mp4 file of the video to my laptop and then I tried to put it into Imovie so I could edit it but for some reason no matter what I do the Imovie file always has no audio even though when I open the mp4 in Quick Time player there is audio. My mic was on the whole time and I have tried re-sending the file but that didn't work. I've tried relaunching Imovie. It didn't work. Nothing is working. Not even bringing the Mp4 straight into the timeline. Can someone please help me out here?

 

[MightyGem]

When you put the mp4 into the Timeline, is there an audio waveform below the video?

 

[Detective Alex]

When you put the mp4 into the Timeline, is there an audio waveform below the video?
View attachment 32559

For some reason it was showing that at the very start and then the rest of it was missing it. Luckily the issue was resolved. I don't understand why it happened but after I shortened it with Quick Time it started working like normal. Now the question isn't how to fix it but how to prevent it right?

 

[MightyGem]

Could be just a one off.