MY ISSUE IS RESOLVED. The duplication occurred only when I had cards in both slots, even though I was only writing to one card. I DID A MARK IV firmware update and it resolved the duplication when connecting USB to import, even if I have both cards i...
I have this exact same issue with 5dMarkIV. This is the first time I've found a forum with someone having this issue. This issue does not happen to me when I'm using the 7dMarkII.
