Odd behaviour on latest blocks

Have noticed we’ve stalled on 570/571 for some time.

Then #571 appears with a timestamp nearly 20 minutes old.
Coinbase out on block 571 already has 2 confirms; and whats weirder is ‘t3Vz22vK5z2LcKEdg16Yv4FFneEL1zg9ojd’ has 576 tx’s (i assume this is the dev’s cut).

Feel free to check:

Is this a repeat of the block withholding attack we saw on Verge/Dogecoindark some time ago, where the difficulty gets ramped up very quickly; then the pool separates from the network and mines ahead?