Yeah, the artifact upgrade bug. It is actually upgrading and will eventually error out when you "run out of silver" or the upgrades finish at 16. Either way, that isn't what is actually happening. It's some kind of server connection issue. Run a battle somewhere and it occasionally fixes it, or restart. Then the actual upgrade progress will show.

Appreciate the info, will give it a try.

Good luck! I have this problem every so often too.