gethnode of mine has 10 bad blocks currently, but all from the Byzantium range (between 30000 and 40000). Gist if someone's interested - some ellipsis in there, though...
veox-parity-renegade. It would seem strange that a node would list a block it's produced itself as invalid. :/
0x7a9a(decimal: 31386); and
eth.getBlock()reports that same block, whether queried by hash or number.