Taxonomy “name” conflict with WP Core

Somehow we managed to have a custom taxonomy slug “type” which conflicts with the reserved one with the same name, which is reserved for WordPress Core.

Now, if I enter to edit this custom taxonomy in MetaBox, it prevents me from saving because of this conflict.

I would like to change this slug to something new in order to correct this issue, but I do not want to lose all terms and entries that are already associated with it.

Any suggestions how to do this the correct way?

Many thanks!