Just last week I noticed the description for the movie "Us" in the HBO Max app on iOS and AppleTV displayed all of the left-leaning and right-leaning quotes and double-quotes as question marks, but displayed ® correctly. My guess is something in their pipeline is using latin1 encoding[1].

Which is to say, just getting everything onto UTF-8 (or UTF-16 if you must) would be a huge win.

[1] https://en.wikipedia.org/wiki/ISO/IEC_8859-1#Quotation_marks