Yes.
The process was:
exported the default example and expanded nr of columns to include my own column headings.
imported that into GD on the site.
when that gave me the “uncategorized” problem again, I exported the example and used it as is, with my own info (three entries).
still put all three entries into “uncategorized”
I am fairly sure that I have read most (if not all) the posts about the problem but none solved my problem, which is why I am convinced that I am doing something wrong on my side and will repeat that because I am in tunnel-vision now.
Thanks for the help