Hey, I’m very sorry you haven’t received an answer so far!
Can you actively get to the resting robot screen (recovery mode power+volume up) to perform a hard reset( 
deletes everything)?
Another thing that comes to my mind since it’s your 3rd FP2 already: Since FP2 can “kill” some SIM cards maybe it could also work the other way around? Have you used the same SIM card with all your FP2s? How old is the SIM?