Canon Printer (MX920) Randomly Keeps Going Offline With New Xfinity Giga Router

My Canon Printer (MX920) keeps randomly going offline on a daily basis since I've upgraded my plan to Giga service and needed to replace my old non-Giga Comcast/Xfinity xFi router with a new Giga-capable one. 

At random intervals, usually after the printer has not been used for any print jobs for awhile, my printer simply goes offline.  I have to turn the printer's power off; then toggle it back on.  A few seconds later the printer is again part of my home wireless LAN and other devices can successfully print to it.  However, it will go offline after it's idle for awhile.  This is now happening on daily basis.  The frequency of occurrences per day is becoming too troublesome to ignore.

This same printer had NO such offline problems with the older non-Giga Comcast/Xfinity router.

Can anybody help resolve this frustrating randomly offline printer problem with the giga-capable Comcast/Xfinity xFi router/modem?

Thanks,

Tony