SMB Read Only - does not work

Hello,

I am new to TrueNas and have got the following troubles.

I have got 1 dataset and created a SMB Share for this. I also created 1 User with Read / Write Access. This works fine so far.

Now I created a User with Read Only. I set the user to Read Only and apply permission recursively to affect all existing folder on my dataset.

Unfortunately it does not work. Any ideas, what I am doing wrong? What information do you need to evaluate?