I have an established WiFi network at my house.  There are usually 20-25 devices logged on.  The network uses an ARRIS W21 with a W21 extender.  It has worked great for 2-3 years.  I have computers, cell phones, gaming systems, security cameras all successfully working.  I wanted to add a 2.4GHz (only) device and so i wanted to log into my router to momentarily disable the 5.6GHz band.  My Surfboard Central app was uninstalled from my cell phone, so i downloaded it and ran it but it hangs because the SC app can’t find the router.  I disconnected all the wired devices (not the cable modem LAN connection) and it won’t connect no matter what i do.  The error on my cell phone is: ‘Couldn’t find your mAX router.  We are not able to find your mAX Router nearby.’  Well, i’m standing next to it with WiFi enabled on my phone….NOTHING.  I’ve spent hours on this.  Please help me re-establish the Surfboard Central app so i can manage the router that is otherwise successfully working great.  Thank you!!