Makes sense. If it gave you an address with an uncompressed private key, then it shouldn't expecting you to convert it to compressed. I believe that these private keys and addresses you've posted are merely to give an example. As for the real ones, have you saved this vanity output from above? Or did you just send money to an address you're locked out currently? You might have done a mistake yourself.

Also, a question that should already be asked: what was the receiving address' type? Was it P2SH or legacy?