I solved it, it was because the _vendor_term_id meta value, wich is used for the vendor shop taxonomy, when i use the custom wpuf form for registration, the vendor has no term_id assigned, so you have to catch the user id after the registration, check if is vendor, and insert a term with user_login as name on dc_vendor_shop taxonomy, then use that term id and save it on _vendor_term_id metakey on user meta. I think my explaination is a bit confusing but is 1.30 am here, if anyone needs me to explain better contact me, topic resolved.
