Unfortunate for the mempool but it’s fair play. Also consider holding a winning lottery ticket in your hand but not cashing it in because there’s a chance you could increase your winnings. But everyone else also has the same chance of winning, and claiming the prize before you do.

So it was you.

Mined just seconds after the prev block, both by Antpool. This just happens unfortunately. If it happens significantly more on some pools than others (proportionally to their share of hashrate), it could indicate inefficiencies in the pool software, inefficiencies in their Bitcoin node configuratio...