nickname can be changed even if it is disabled

Dear developers,

In my server, to allow newcomers (without a role) to rename themselves, I let the "change nickname" permission. And I disabled this option for people with a certain role. Except those who had this certain role could rename themselves.
Is this normal?
I used the same logic as when a person without a role can write in a living room but not those who have a certain role. (And here it works)

Thank you for the work you do every day,

Best regards