Controller-less WLANs

Q:

Why does MESH stays disabled, even after disabling Extended SSID ?
 

In a default configuration, we might sometimes notice that Mesh link doesn't come up, even though the Extended SSID is disabled.
This is behavior of IAP, that when you disable extended SSID, it is only disabled in configuration, but not in state. 
So to disable it we must also configure a new SSID so the default SSID gets removed.
Once we do that, and create a new SSID, the default SSID is replaced and also lets the mesh link to be up (once Extended SSID is disabled).