I always have the Incremental Ingest box ticked when ingesting images and it's always worked well with cards from any of my Canon cameras, however, when ingesting frpm either of my Sony A6000's it seems to ignore my request and re-downloads anything on my cards that I've previously downloaded.
As an aside I always get an error message that one file on the Sony's cards was not downloaded, although that in itself is not a problem.
Any ideas as to anything I can do to stop the duplicate ingest?