The PBS app on Apple TV offers an "Up Next" feature. This feature automatically plays a new video once your currently viewed video has concluded.
This feature can be disabled after a video by selecting the Dismiss option on the left side of the "Up Next" prompt or by exiting the current video before 30 seconds have passed.
If you wish to disable the feature entirely for the channel, open the Profile menu on the left side of the PBS home screen.
Select the Auto-play Next Video option to switch it to Off from On. You can return to Profile menu at any time to turn it back On.