iTunes subtitles on ATV4

[talkingpictures]

I've recently bought an ATV 4 and one of the first things I did was change the subtitle appearance in the settings to display subs across all apps, Netflix, Prime Video, Shudder, YouTube etc using my style preferences. Yesterday I connected my Movies Anywhere account to iTunes and upon playing certain movies through itunes, I noticed that some titles had small size subs whereas others the subs were higher up on the screen and didn't stay in the middle, one character spoke and subs moved to the left, the character in the right spoke and the subs moved to the right, these titles were Sisters, Man of Steel, Enter the Dragon and The Night Before. When I tested Ouija Origin of Evil and Secret Life of Pets the subs were fine again.

Is this something to do with the titles UV settings? I assumed they would play in iTunes using their copy and my subtitle preferences should stay intact.