Videos on Phone have a video delay?

[AC Question]

Phone: Samsung Galaxy S7 Edge
Update: Nougat
Application: Gallery and Video Player (Pre-installed apps)

I have some videos on my phone (.mp4) but the audio and video are no longer in sync. There's about a 1 second delay (Audio is 1 second ahead) and I don't know why it has happened! The weird thing is that some of the videos have been unaffected and are all fine.

I have the exact same videos on my computer (Apple macbook air) and everything is fine!

Does anybody know what happened and how to fix it?

 

[B. Diddy]

Welcome to Android Central! Are these videos saved to Internal Storage or the SD card? If they're on the SD card, see if the same thing happens if you copy them to Internal Storage.