Yeah, I observed exactly the same problem - it failed for balance in round #4679 and #4680, even if balance is - of course - right (over 3mio XEM). If this happened (happens) only for a part of supernodes, I hope it will be recalculated for the right reward after solving this issue.
And anyway, about the rewards - I’m still waiting for the payout for rounds #4673-#4676. It should came yesterday (2019-03-14) around 14:00-15:00 GMT, but nothing arrived. Did anybody has the same experience ?