I have several clients that have this same issue where one or more APs become a Master also. Here is what I mean when I login to what I know to be the Master dashboard with a static IP, one or more APs are disconnected which are DHCP. After a bit of hunting for the other APs IP I am able to login to those disconnected APs and one of them are also a Master.
My only recourse, that I know of, to put them back on to the Master that I want is to remove the disconnected APs in the Master dashboard and then reset them.
It's as if the communication between the master that I chose and the other APs are lost for a little bit (hour or so?) one of the others take the Master role. Once the communication is restored, the role doesn't reverse and the original master is still the Master while the other APs is also a Master.
Advice?