Web portal and remove "Send invitation" and "Change password" ribbon buttons

Hello community,

We have deployed web portal add-on. On the ribbon of contact form we have two buttons "Send Invitation" and "Change password".

I removed all permissions in user security role on  adx_invitation entity. The button "Send Invitation" is still here. If I click on it I get a new Invitation form in read-only.

Is there a way, either by removing permissions on security role, either by removing permissions in a web role to remove these two buttons on contact form ribbon ?

I don't want to have to edit the ribbon to remove these two buttons.

Thank you for your answers,

Julien