[roguexuk]

Originally Posted by gbm

Rename them:

 Fanfic.The X-Files
 Fanfic.Avengers

see https://manual.calibre-ebook.com/sub...roups-tutorial

bernie

Ooh, great. Will have a go & see if it works.

EDIT: So far, so good. I've just tried adding my problem tags onto my Clara using the genre tag hierarchy thing, and no problems - they add and I can still sync my Kobo!
I'll try adding all my other tags this way & hopefully it'll still work for me :-)

Thanks for getting me this far.