It's happening here, too. Recently watched Good Omens, and it would skip ahead to the next episode, but we were able to work around it. Last night, though, we tried to watch the first season, first episode of The Expanse, and just as soon as the opening credits were over, it skipped to episode 2. We never even got a minute into the first one! We tried three times, and just gave up.
We are watching on a Samsung TV, through a blu-ray player (that's where all my apps are... it's not a Smart TV).
We don't watch Prime Video very often... but if this is how it behaves, we'll probably give up completely. Just too frustrating.
Edit: I disabled AutoPlay.... then made sure my blu-ray player was updated (it was). Then I tried again. Same thing. Only now, because AutoPlay is OFF, as soon as the opening credits are done (actually, BEFORE they are done), it jumps to the Prime Video screen, with a thumbnail of Episode 2. So, it's still messed up!! This is not acceptable!
I am also encountering this issue on the Roku app. In the case of the show I’m watching right now there are still seven minutes left in the episode. There is no option in the settings to turn off auto play. It appears that a lot of people are having this issue and there is no resolution. It’s really shaken my faith in the service. I don’t want to get interested in a show just to find that I can’t watch it. If I can’t trust that I’m going to be able to watch a whole episode, there’s no reason for me to watch (and pay for) this service.