I wonder if that’s something you could get better at with practice? When I watch subtitled movies or shows I watch the show and read the text with my peripheral vision. But I watch a lot of foreign media, so I may have gotten used to doing that. I can say for sure though that my eyes are not focused on the text while watching.

Absolutely! I grew up in a country with fairly high rate of literacy, which derived subtitles usage almost 100%, and reading them while enjoying the original voices behave second nature, and what's never fully translatable led to learning foreign languages specifics. Even today, so many years later, I like my movies with subtitles, and even when spoken language is same with the subtitles one.

I highly recommend original language + subtitles in original language when you try to get better at that language.

I honestly wonder if this is a reading speed thing. I don't notice keeping my eyes on them at all.