Welcome to the Roku Community, @MsBatty!
We appreciate you reaching out for support and we'd be happy to help you find the best resolution possible.
We completely understand how important it is to see the very end of the movie, especially for this kind of show. You can actually disable the autoplay feature on your Roku device under Settings > Accessibility > Auto-play video > Off.
Roku will make your auto-play preference available to third-party apps, but some apps may have their own auto-play setting. If you are in an app and videos still automatically start playing as you navigate, check the app you're in to see whether it has a setting to control auto-play videos.
Here's the support article for reference: How to change the auto-play video setting on your Roku streaming device
I hope you find this information helpful.
Best regards,
Carly
Carly Y.
Roku Community Moderator