My Samsung TV Crunchyroll app has the ability to disable Autoplay to next episode but my Roku Crunchyroll app doesn't have that option.
From Crunchyroll Customer Support...
"If you'd like to stop the autoplay feature in anime, you can simply start a video and then click on the settings button. From there, you will find the option to disable autoplay."
These are the only options I see in my Roku app
Audio
Subtitles/CC
Captions Styling
Closed captions