iPhone 12 video is normal speed but sound is slow motion

Hello GastricReflux,

Thank you for using Apple Support Communities. Sounds like you're experiencing some issues with video you record using your iPhone. We'd like to help out. It's also good to hear that you're fully updated on your iOS version. There's a couple of basic steps you can try to help further isolate this issue you're experiencing. Try these steps below:

1.) Close the Camera app: Close an app on your iPhone or iPod touch - Apple Support

2.) Refresh things by restarting your iPhone: Restart your iPhone - Apple Support

3.) Double check your camera settings: Change the camera’s video recording settings on iPhone - Apple Support

You also asked if there's a way to fix the videos that are affected. You would have to edit your videos using video editing software such as iMove or Final Cut Pro X. iMove is available on your iPhone:

-Edit audio clips in iMovie on iPhone - Apple Support

-Edit audio clips in iMovie on iPhone - Apple Support

We hope this helps you. Thank you for using Apple Support Communities. Take care.

Hi GastricReflux,

With the details shared, this does appear to be the best help direction to assist with moving towards a solution. If everything shared has been checked and exhausted, your next best step is to contact Apple Support to further investigate this and determine the best path to a solution.

Take care.