Actually I think that issue is to do with the genesis id / hash stuff being missing in the block transactions…
@Sowna you can probably fix it by iterating over the transactions in the block and setting the missing genesis field(s) (I forget which ones but I think Fabrice linked to them). The TxId is a computed field, and when the node returns the transactions in the block, it “compresses” out the fields that belong to the block. Those then need to be re-added into the transaction to get the right id.
However, I should probably add a utility method in the SDK to be honest.