How to connect Smart plugs and lights

If those devices only function on the 2.4 GHz WiFi band, see below;

The two WiFi bands SSID's have recently been combined into one with the Comcast gateway devices. Some devices get confused and don't know how to see / talk to combined SSID's.

If you are not using any Xfi Pods, you can try separating the 2.4 and the 5.0 names and give them two different broadcast names / SSID's;

https://www.xfinity.com/support/articles/change-wifi-mode-admin-tool-xfinity-xfi 

Associate the devices with the 2.4 GHz band's (broadcast name) and password.

I succeeded in getting VOCOlinc smart plugs to connect with my new xFinity xF1 router and appear in my iPhone's Home app, but it was an adventure. Take notice that this new router does not provide for separating the two wifi bands.  Supposedly the xFi determines if a new device requires the 2.4ghz band and, if so, provides the connection to that band.  I eventually found that that is true.

I first deactivated my 3 pods.  I'm not sure if this was necessary, but I knew it might help.

I plugged one of the smart plugs into a GFI socket in a part of the house where I knew the wifi signal from the router was strong.  I plugged an LED light into the smart plug, turned the smart plug on by pushing the manual button and switched on the light.  Again, I'm not sure if I had to do any more than plug the smart plug into the wall socket, but this would prepare for eventual testing.

I then went into the Home app and tried to add the new device.  It timed out in a couple of minutes without having detected the plug.  Tried again, no luck.

I downloaded the VOCOlinc app from the App Store and tried to activate the plug with that app.  No luck.

Finally, I moved the smart plug with the LED light to a different wall outlet, one slightly closer to the router.  The Home app then was able to find and connect with the smart plug.  Now everything works.

Why didn't the set up work with the first wall outlet?  Sorry, no idea.