Hello Jim,
Thanks for reaching out to Apple Support Communities. We've reviewed your question and it looks like you’re unable to play videos on your iPhone. It's understandable that you'd want this resolved, so allow us to assist with that. Please start by taking a look here: If you can't watch or stream movies and TV shows in the Apple TV app
We also advise taking the following steps, which may help with this unexpected behavior: restart your iPhone, make sure it is up to date and close the video playing apps and reopen them.
1. Restart your iPhone (you mentioned doing this already, which is a great step to take)
2. Update your iPhone, iPad, or iPod touch
3. Close an app on your iPhone or iPod touch
If you have follow-up questions, please let us know. We're here for you. Have a fantastic day!