Why does continuous play stop at episode 6 in the Apple TV app on iPad?

I have Backyardigans downloaded in the TV app on my daughter’s iPad 10. I have continuous play enabled (play next episode) and I will play the next episode but it stops at episode 6 and then does not play any further. The whole season 1 plus season 2 is downloaded so I’m not sure why it keeps stopping at episode 6?