Seems like there was a whale miner who jumped in a few blocks earlier (the Π effect on the difficulty) and left prior to cracking that one block and then the rest had to process the increased difficulty. Glad these occurrences are only for one block and not for days or weeks
Yeah diff jumped to over 400 for a few minutes. You sure it was from a whale miner? I didn't realize something like that would have that kind of effect so fast.
I can't be sure because I wasn't monitoring the hashrate at the time, but it had to be, otherwise there's no reason the diff would spike for several blocks.