Home Movies Cannot Play & iPhone Videos Distorted

A two-part question/problem:

First, it seems like all home videos I’ve taken with my camera (1080p) receive a “There was a problem playing this item” message. I’ve searched the forums and Google and all the comments I’ve seen relate to insufficient storage. However, I have over 4 TBs of free space at the moment.

The second issue I’m running into is that all videos shot with iPhones are distorted. Is there any way to fix that?

I’ve only had my server up and running for a few days.

Edit

The iPhone videos play without distortion on mobile devices; it only appears to be an issue on TV and computers/MacBooks.

The home videos shot with the camera buffer indefinitely on mobile devices, but the “There was a problem playing this item” message does not appear.