Why does my cable modem/router keep switching channels? [View all]

Recently my cable provider set us all now router/modems promising higher speed with no price increase. (I'm waiting for their follow-up offering me ocean front property in Az.) Yes, we got faster speed, but...

There seems to be an ongoing issue. Periodically I get errors like the following on my troubleshooting logs on the modem/router:

Thu Sep 15 08:52:30 2016 Notice (6) WiFi Interface [wl1] set to Channel 149 (Side-Band Channel:N/A) - Reason:INTERFERENCE

Whenever one of these errors (Yeah, I know they call it a 'Notice') occurs, all connected devices fall off-line and we have to retry our connections (often getting either a 'network change detected' or a DNS error) several times to get reconnected. It also screws up my wireless printer, which then becomes a pain to get back to a point where I can print to it.
These errors are very sporadic. I might go several days without any. I might get one in a day, or I might get 15-20.

So, the question is: What sort of 'interference' could be causing this? Is there any king of shielding I can put up to reduce 'interference' or ...?

I am running Windows 10 on my computers. A fully wireless laptop, a desktop that uses a neat little adapter that basically runs the modem signal through my house wiring, and a couple of tablets running android (also wireless).

Any comments, suggestions, or deeper explanation of what the heck is going on appreciated.