4K movie rentals stop after 5 minutes

I have an HR44-500 with a Gemini 4K box. Today, I tried to rent our first 4K movie since getting the Gemini about six months ago. The movie plays for five minutes, then stops. The screen goes black. I can’t rewind or fast forward.

After contacting customer service and not getting resolution, I thought it might be an issue with the movie itself. I just rented another movie. Same problem--movie plays for five minutes, then stops. 

I reset both the HR44 and the Gemini and confirmed our internet connection can handle 4K. We did have Movies Anywhere enabled, but I’ve just disabled that.

Customer service tried basic troubleshooting but couldn’t help me. Any ideas? 

Thanks.