No way. I don't know why but it has been impossible so I take the easy way: I opened a new kobo account. Mostly my books are being buyed on Amazon.
I have been wasting the morning trying to do this I suddenly I decided it was enough. Definitely kobo collection 1, me 0

The collections which I have been having issues are the ones I had in my old kobo mini. Now I'm going to start again.
Thanks for all the support.