This is on a fios based POTS voice line without advanced features ( Like caller id)
My phone rings and I pick up and I hear ringing ( 4 or 5 times), then someone pick up and they say hello and it looks like I am trying to call them. I say hello and the other party is curious why I am calling about. This does not seem like a scam to me
call repair. You have regulated POTS which they are obligated to fix promptly. The Fios fiber part is just the delivery method, shouldn't have anything to do with the scrambled dialing you are experiencing.