Catalog Import and Keywords

I have an Aperture Catalog I have been trying to migrate to Capture one Pro for several months now. Here is the latest glitch, it looks like I have to give up the new COP8 catalog and start the whole process over.

It seems that if permanent keywords for the filter tool are added (via plist editing) then these are kept separate from identical key words which are already assigned to images. You now have two identical keywords.

I first restructured my Aperture keywords into COP8 compatible format so: "Top Level | Next Level | Keyword" (about 500 keywords in all). Then I broke my Aperture library into chunks of about 4500 images each. I have imported the first two chunks, so I have 9500 images in my main COP8 catalog.

Then I realized that the keywords associated with the images do not show up permanently in the COP8 Filter tool.

After some research I exported the Aperture Keyword hierarchy, and edited the COP8 Plist file to add this keyword structure. In an empty catalog, the keyword structure from Aperture shows perfectly. But when I load my main catalog with 9500 images, the newly entered keyword structure shows separately from the key words assigned to the images when already present, even if they are the same. I have several lop level keywords "Topic" "Style" "Event" - they all show twice in the filter - the ones added via the plist are empty, all the existing keywords are attached to the other one with the same name.

I tried starting a new catalog, and importing an Aperture catalog, in this case the imported keywords are correctly combined with the permanent ones.