Doesn't that coincide with that massively botched HF where the blockchain was inaccessible for several days and (as I recall) was mired down in replays? There was also an occasion on which the rewards pool was reset(?) somehow and rewards all but dropped to zero while the pool was coming up. I remember having $30 posts one day, and then suddenly having 10c posts...

That vaguely rings a bell. I was a clueless noob back then.

Now a clueless veteran.

Not sure if it was a HF, as they are split. There was the RC HF that stopped people posting, but I think that was the end of 2018, wasn't it - I am getting too old to remember! :D

Not sure, that whats in the hivesql. Might be due to some hardfork, and tempary stop of payouts .... i was not around at the time :)