After a few tests, it looks like an IP blocker, I have ones that work and those that don’t. Some work again after a few hours of rest.
The situation looks similar to downloading account data.
I’ve noticed too that I can no longer browser more than 40 posts from any user via the web without getting prompted to login. I assume it is roughly the same for scraping.
Yep, it should be definitively a kind of IP blocker. I have the same issues, with some proxy it works and with some not! I also read that Instagram is going to hide any public information without login, but also here I think it’s still with an IP blocker