Ask HN: Why is TikTok’s FYP algorithm so geographically weighted?

I live in the US and travel to Italy for about 2 weeks every year. I use TikTok on a daily basis.

When I’m in Italy my feed features a lot of Italian language content. I don’t speak Italian. It feels like TikTok should “know” that I don’t care for Italian language content by now. TikTok clearly overweights geographic location, and the degree to which it overweights hasn’t changed since my last annual trip.

I haven’t worked on recommendation algorithms. Why do you think this problem of geographic weighting is so hard to solve for?