Ask HN: Security bug in Threads-Instagram-Meta signup?

I'm trying Threads, and seem to hit a security issue. Is anyone here seeing similar? And/or how to diagnose this issue?

1. I install Threads on a typical Google Pixel. Threads successfully connects to my Instagram account.

2. The next time I use Instagram is on my Mac. There's a warning that says Meta suspects unauthorized access to my Instagram account, and directs me to change my password.

3. When I follow the directions, I see Meta account account settings. However, everything is in Swedish, which I don't speak, and don't use. There's no obvious way to change to English.

Questions: Is anyone else here getting these kinds of warnings? And does anyone here have backchannels at Threads/Instagram/Meta to let the security team know, and the i18n-l10n team know too?