something is wrong when I send a transaction from address 67 signed by any privatekey through this service (
https://slipstream.mara.com/), it says that:
"Transaction already exists in mempool, add a higher fee."
does this mean that if you sign a transaction with the correct private key, the service will respond with the same message?
It looks like this is because I sent an unsigned transaction to Mara, because
https://coinb.in/#sign does not sign the raw transaction with the wrong private key, but simply returns the raw transaction unchanged in the field where the signed transaction should be.