Occured out of nowhere (no action/nothing changed on my part) a few days ago.
Attempting to access Intel on any device renders "account not found" message.
Tried all standard tricks, no change.
Core member and agent since 2014 // Sindaya
I have the exact same problem, i can't access Intel at all
I linked a brand new FB to my account as this was what support suggested (and since Intel suddenly didn't find my account when using my gmail).
Didn't help. Not even after the latest update where the fb login bug was supposedly fixed.
So still can't enter Intel (but accessing Prime, Wayfarer, Missioncreator and obviously the Forum works fine).
Support is telling me they are "looking into it", and knowing people have been stuck with this same issue for 6 months+ I suspect they have no clue.
Sad thing Niantic can't solve basic account/login issues and security. The way I play no Intel means no Ingress.
I have same problem. And in-app support system is not responsive enough.