Sim card randomly not readable?

[Iamallama]

Using a Sprint Galaxy S8 that I've had since October, last night I lost network connection. Setup Wizard says SIM card is not readable, Phone says invalid SIM card.

If I restart it or pop the SIM out, the phone passes the Sprint OMADM device check and operates on LTE for approximately 5 minutes before the error returns.

I have tried the following simple fixes:
All latest updates
Restart
Power off, wait a few minutes
Popped out the SIM, wiped it, reseated, and blew in the slot
Wiped the cache partition

My thought is my SIM randomly died on me, but if there are other things to try before taking a trip to the Sprint store... I'd greatly appreciate the advice.