I have been using different Roku players for nearly 10 years now. I currently have a 1st generation Roku Streaming Stick (3400 series)
A strange new issue has started occurring within the Amazon Prime Video app in the past several months:
I use my Roku and Amazon exclusively in English, but certain programs (not all) have begun displaying program description text in Spanish! (The audio is still in English and there are no subtitles.)
For example, in my Watchlist, I'll see "The Marvelous Mrs. Maisel", but when I click on a season or episode, it appears as "La Marveillosa Sra. Maisel" and the plot description is in Spanish. This is a US-produced, English-language program that I have only watched in English without any subtitles. Another example: "Tales from the Loop" episodes are described as "Historias del Loop" with plot summary in Spanish.
This only happens on some, not all programs. I have tried restarting and signing out of Amazon on the player.
You need to contact Amazon. Roku has nothing to do with what displays in a channel developed by someone else.