What could be causing my Roku to freeze and restart?

It’s a known issue with the HBO Max app. Did a quick Google search, and there are tons of references to this issue. Here’s one.

I had a problem with freezing on my Hisense TV when using YoutubeTV through the youtube app that the TV comes with. Regular youtube worked fine and so did Netflix. It only happened on youtubeTV when watching live TV or a recording that had been done less than 24 hours before, and was fine with older recordings.

I tried everything I read online and what just seemed like it should work intuitively, but nothing worked. I finally broke down and bought an Amazon Stick and it works fine. I know nothing about Roku or if my experience might apply to your problem.

Particularly because of what @hat wrote, this sounds to me (software engineer, has worked on media streaming stuff), like it is their bug/issue. Your own devices (Roku, router, Internet connection, etc) are probably all fine. So probably all you can do is either avoid those services, pre-record their content somehow, or suffer through those delays until they fix their issues on their end.