On May 28th, according to mempool data, miners mined an empty block (a block that only contains the block reward Coinbase transaction) at Bitcoin height 845484, with only a 40-second interval from the previous block height.

Miners package empty blocks for economic reasons, which is the wisest choice for them. In order to fully utilize this time for mining and avoid conflicts with transactions packaged in the parent block, miners cannot fill the block with transactions, which means they can only attempt to mine empty blocks.