I have just started using digiKam and is still trying to get a grip on using tags and metadata. My images already had hierarchical keywords in their metadata and mostly digiKam added this to a hierarchical list of tags the way I expected. However in some cases the hierarchical keywords are interpreted by digiKam as just one (long) tag. Not sure why and it would not be a big deal if I could just edit or delete these keywords in the metadata.

However this is my problem: I can't seem to find a way to edit those keywords in the metadata. From what I can see they are in the IPTC part of the metadata. Is it not possible to edit this? It seems to be in the editor but when I do edits they don't save.
Using the tags in digiKam I can of course delete the tags in question or merge them. However when I do this it still doesn't look like the tag corrections are actually also corrected in the IPTC keywords in the image metadata? I would like it to be so that I don't have to do this work all over if and when I ever need to add the images to a new digiKam installation or another manager that reads the image metadata the same way.
I have looked in the Recipes Book but have not found anything regarding this particular problem.