@JustReboot 

If you were to power down the satellite P9 units do you still experience the same issues you originally described?

@Tony Not only did I power off the p9s, I actually reset all of them [including the main router] and changed the name /pw of the network (forcing me to rejoin all my devices including the TP outlets, ring etc.

I was willing to go through that, and all was well until this am when the on /off started happening again. This is very frustrating and may require me to return the system and go back to Netgear. I was getting some dead spots with them, but at least the system was solid. Please let m,e know. Again the Macs are less than 5' away from the main router. The one I am on is about 2' away. 

Also all this time the p9 units have stayed solid white - never flashing.

@JustReboot 

The P9 does not have the ability to access it with a browser yet.

If you are noticing all around slowdown of speeds you may want to connect directly to the modem, look at the modems system logs. Should the logs have critical 3 errors, then your internet signal quality is bad which gives you the poor internet reliability.