Uhh... that's kind of how these algorithms work. I presume you interact (i.e. don't scroll past) with a lot of the English posts. It's going to index on that and show you more English content. When I'm abroad, I might see a few posts in their native language but the algorithm will revert to showing English posts about the city/country once it realizes I'm not really jiving with Portuguese posts, for example.

An illiterate coworker of mine showed me his phone and asked for help. It was utterly amazing, he exclusively got videos from goat and donkey farmers. The most stunning part was that most of the videos were completely hilarious. People talking to their goat then the goat does what they say or the opposite on purpose.