Android phone cannot connect to internet via wireless, other devices can I recently installed a new cable modem.  After getting everything up &amp; running, I can connect to the wireless router, and then to the internet, through laptops, desktops, and a Roku device, but I cannot access via my Android phone.  It connects to the router, but cannot get to the outside world.  If I turn off the wifi, then I can connect via my data plan, but I cannot connect via wifi.

Some details:


The phone is a Samsung Galaxy S3, and the Android OS is 4.1.2
I use Comcast for cable internet.
The (old and unchanged) wireless router is a Netgear device.  (I am not sure the model number, but I can get it if that seems pertinent.)
The new cable modem is also Netgear.  It's model CMD31T and it is DOCSIS 3.0, while the old modem was quite old and I have no idea what it's level of throughput.
I changed to the new modem because the old one was becoming "spotty" -- it would occasionally lose signal.  The new modem has so far been consistently on, and with strong signal... it's just that the phone cannot connect to it.
Well, now the phone can find the signal fine after a few days.  I did NOTHING different.  However, I had taken many steps beforehand, such as updating the firmware, PRL &amp; Profile, restarting the phone, restarting the cable &amp; router.  None of those actions worked, however just waiting a few days seemed to resolve it.

This is not much of an "answer", but I am keeping the question &amp; answer so that if anyone else has troubles, maybe theirs will also be resolved by "just waiting".