Gateway user manager and user_ex table

Hello, I’m using a custom implementation for user management, and I’m using the table users_user_ex to store some extra properties related to each user. I made a Perspective view to add/edit users informations and everything works well, but when I try to edit some user from the gateway interface all the extra informations stored in the users_user_ex table related to that user will be deleted: is there something I’m missing or is it an Igntiion bug? I’m using version 8.0.16.
Many thanks in advance,
Francesco