I just upgraded to a new Apple TV HD with the 2nd gen. remote. I often watch foreign language shows on Amazon Prime. If I forget to turn off the subtitles there before switching to Apple TV+, I see no way to turn them off in the Apple TV+ app. I have to go back to Prime and turn them off. Then return to Apple TV+. The instructions on Apple's web site don't jive with what I see in the app.
The down arrow (while playing a title) works as described in Control what’s playing in the Apple TV app - Apple Support works on my Roku on Apple TV+, Netflix, HBO Max (but I don't remember if I've used it on Amazon Prime).
For Apple TV HD or later models with tvOS 15 or later, use this guide:
I have no problem turning subtitles on or off in Amazon Prime. But pressing the down arrow does not bring up the subtitles option in the Apple TV+ app. I just tried it again tonight.
How do I turn subtitles on/off in Apple TV+?
