Multiple Nighthawk EX7300 Extenders

The extender mesh options work great when there's only 1 mesh extender. Once you get 2 extenders is where you run into issues. Reason why is that its not a true mesh setup in that nothings controlling it. (router/controller). This is what allows it to function with 3rd party routers. 

the workaround to get it functioning it so make sure one of the extenders isn't running in mesh mode. otherwise they can connec to each other if they can see each others ssid. 

so try this.

router---->extender with mesh ssid------>extender with unique ssid. 

or  Extender in mesh<------->router<------>extender with unique ssid.  

this prevents them from connecting to each other.

Its kind of a pain as the whole benefit from mesh is to have 1 ssid. But again, the issue is that its more of a hybrid mesh and not a full mesh like orbi. To get a full mesh, you need to actually move to a mesh network and not whats offered with the extenders. Its why I've always recommend to people who need more than 1 extender, to move to orbi or a similar mesh setup.