Lightroom to Flickr gives duplicates images

I having an issue in Lightroom 7.5 on my Mojave Mac when I load a modified image to Flickr. Instead of replacing the image I am ending up with a duplicate. 

I have a Pro Flickr account and have been able to update images with no issues but I am now getting dupes every time I republish. I don't think it started right after the Mojave upgrade but I don't recall it before either. Anyone have any thoughts as I am at a standstill ATM.

Additional - I have just been back to take  look at some earlier uploads and it was happening before the Mojave update. It *seems* that any image that is updated creates a new version.

This is 100% repeatable and has affected many hundreds of different images