[calvinbhai]

Possibilities:

1) you have instagram or whatsapp and use them frequently

2) you use an app that has Facebook login, that has location access or just has the SDK lying in app but not being used.

3) I don't know about what access react native/js frameworks have in terms of device resources, but that "may be" an another source of info leak.

4) your contacts/friends uploaded a photo on one of these services where you were there in the photo

5) if any of these apps have microphone access (when you record videos) it's "possible" to do many surreptitious things.

All of the above, done by 1 or many of your friends/contacts on Facebook/instagram/WhatsApp, FB identified you and correlated it somehow.