I have 13,000 images that have been extensively tagged in Daminion on my NAS drive. Daminion writes the tags directly to the IPTC section of each image and, the way I have it set up, does so immediately I make any changes so I know that my images exactly mirror the tags applied in the app. (If, at this point, you are wondering why I do my tag management outside LR, it is because I find it just so HARD in LR. )
I exported the tagging structure and tags to a text file which I then imported into a brand new catalogue in LR. The import process worked beautifully and my entire tagging hierarchy and tag names were faithfully replicated in LR.
Next, I imported the images from the NAS drive. I quickly aborted it when I saw that LR was ignoring every entry in my imported hierarchy and was creating its own new ones outside the hierarchy. And it did this for every single image it processed.
Which leads me to ask, "What did I do wrong?" I thought I had followed the logical path but obviously not!