EX8000

My EX8000 extender will simply not pick up the 5GZ from my ax6000 extender. It pick up the 2 GZ fine.

The ax6000 is connected to a netgear router router

The nighthawk app is absolutely useless, keeps locking up, failing to recognise my extenders etc. basically unreliable.

I am at a loss and the support given by Netgear is about as much use as the nighthawk app!

Help