CPT Category Aromatically renames Slug to hyphen and number

Hello,

I have a multi language setup using WPML @ http://www.tourpass.rio, most of the CPT categories are fine, except the link below were the slug was renamed with an hyphen and a number, everytime I update it it goes back to the hyphen and number, I deduce it might be to avoid duplication, but I checked in all languages and the category name doesn’t exist, is there a trash of categories? how can I dump it? I did find was tags with the same name of the category, may that be an issue? how can I rename the following CPT category (Museu) without hiphen and number?
http://www.tourpass.rio/locais/museu-1/mast-museu-de-astronomia-e-ciencias-afins/