I was just checking in to see if it was just me. I was in the process of getting a 500 Iso "bonus award" (formerly SHIELD Intercept,) and it stated it couldn't give it to me because of a network error, but then looped back to the bonus award. I closed the game, tried to get back in, and sure enough it's giving me "Check Internet Connection."
Makes sense, some things are done client-side rather than server side, so sometimes you're going to get to do things before the game realizes it can't talk to the server.
Hope it comes back soon, I have a 4* cover expiring in an hour...