According to my wifi, extender and the wifi signal strength app on my phone, I have excellent coverage all over the house. But, I'm having problems with the Echo calling feature and in-home intercom feature. It's like a bad cell phone connection. I've noticed that the green spinning ring isn't a constant green. Thru out the troubled conversation it goes black and then back to spinning green, repeat. I don't have problems with any of my other wifi enabled devices. I don't have problems with the Dots streaming music. I wonder if I need to change them to a 5Ghz channel (or can I?) Two of the three Dots that I've used while trying out the intercom are within 15-20 feet of the router. With Wifi Analyzer one registers -42 and the other, -44. Any suggestions?