My system design like this.
I have active RB750 hotspot and link to RADIUS and add A & B in user-manager.
RB750 ether 1 connect to internet.
RB750 ether 5 connect to ASUS wifi. and ether 5 do not set master port.
My question is : why A use name and password to access internet than B no need password , and B also can access internet. WHY ?