Once c-cex admin is available this can all be resolved.
Its not his fault. We will fix this. Wallet might have too many connections. Might have bad nodes. There are multiple possibilities.
if you don't have a checkpointing server running then its your fault for not having one.
in a proof of stake coin you must have a checkpointing server or it will fork.
But transactions from other exchanges were working smoothly, so my thought was that maybe c-cex.com needs to just resync their wallet. Is that not a possible cause?