Dave,
Weel the 426 code from FTP means the connection was closed but it is transient so it can be retried.
Since the files got where they were supposed to be intact, I suspect Cloverleaf(R) is reporting the error then retrying and suceeding on the retry.
I believe there are settings that can be made on FTP Servers that could cause this kind of error (and adjusting them may resolve the issuance) but I don’t recall what they are.
Compounding the troubleshooting is the transient codes (those starting with 4) are subject to the interpretation for each system – so the server you are interacting with may have a slightly different meaning for a 426 than that stated above.
email: jim.kosloskey@jim-kosloskey.com 30+ years Cloverleaf, 61 years IT – old fart.