I have Kleopatra, but what I want to know is: when you signed the message, did you use my public key or your own public key? 
I use my private key to sign the message to you, not your public key, as it has nothing to do with this process. You can use my public key to verify the validity of the signature, and I can use your public key to encrypt a message for you, and you only by using your private key, can decrypt it.
If you want, you can send me private messages to test, and I will reply to you with other messages.