The issue is on the back end of Steem not the frontend of SteemIt. Bandwidth regenerates and the amount available constantly changes.
I think you might have seen a coincidental "fix" from clearing cache.
(I was getting this error going directly thru the steemd)
That's possible. Multiple occurrences of success by clearing cache would tend to contradict the likelihood of coincidence. From a statistical perspective, I've only seen the problem and solution twice, which leaves plenty of room for coincidence.