Subtitles

[Abi881]

I've just got sky glass and upgraded to sky cinema.
Why are the subtitles not only too big, but they move from the middle to the side throughout. 
Not only this, subtitles are not available on ultra HD or a lot of purchased content. 
its 2024 and this is such a basic accessibility feature that people have been asking to be sorted for years! 
why am I paying for content that my Deaf son can't even enjoy!? I'm absolutely fuming!