Add media button missing

Hello,

I have not seen it before but since 3 weeks, the “add media” button is missing when I add a event with user with “event contributor” and “event publishier” : event contributor with publish right.
Before, the button was here.
The button is still here for admin user.
I try to check differences about the rights between these 3 roles but can not find something.

Can not find why it is missing.
The button must be here, is not it ?
An idea please to display it ?

Thank
Vincent