According to Bitcoin Cash Fork Monitor on the block 557301 Bitcoin SV has undergone so-called “attack of the reorganization” which allows you to delay the process of carrying out a transaction or to skate them back.

Experts BitMEX Research noted the reorganization of the two units and think that PoW-blockchain that is not enough to confirm the fact of attack. In their opinion, the most likely problem is not caused by attackers, and the fact that the blocks were too big (13MB and 16MB), and any interruptions in the connectivity of nodes in the network.

Our Bitcoin node SV experienced a 2 block re-org at block 557301.
In our view, 2 blocks may not be sufficient to conclude its an attack (false flag or not)

— BitMEX Research (@BitMEXResearch) November 19, 2018

Recall cryptocurrency exchange Kraken has warned users about what the token BCH SV “does not meet the usual registration requirements” on the exchange and should be treated as extremely risky investment project.