New Airport Extreme and iPhone Issues

I've had the networking day from ****. I previously had a 3rd Gen Time Capsule at our restaurant, connected to a Cisco 26port gigabit POE switch and Comcast digital voice and internet. Over the past few days, employees have reported trouble accessing the the Wifi network. After several restarts and firmware upgrades (including the dreaded "firmware problem" to fine update), nothing worked. I changed channels, back to auto, back to specific channels, back to auto. Made open guest networks. Nothing worked consistently. My iPhone might connect and my friend's might not. Nor his laptop consistently. Our Axis network cameras might take a bit extra time to connect. All quite random and quite frustrating.

So I swap out an older Airport Extreme (4th gen I believe) using the same configuration as the TC (Time Capsule). It works fine, except for the last port not working as expected. No matter, I plug the mac mini into the Cisco switch and off we go. Nevertheless, I'm still told we are suffering random Wifi issues. So I buy a brand new AE (5th gen) today to replace that one. Should work like a charm I thought. Right....

Several hours later, I finally have the new AE working, but only after doing several hard resets/factory restores, the works. For some reason, the mac mini could not successfully update any of the connected AEs - whether connected directly into the same AE, or if the Mini was connected to the switch. Nothing worked. Every time I tried to update the AE, it would hang and force me to unplug and plug it back in. It would also never save setting changes. I finally resorted to a friend's macbook to be able to restore it successfully. And once that worked, the mini was able to update the AE flawlessly. Our Point of Sales (POS) machines connect fine, our cameras connect fine, wifi printer connects, and the mini connects, and everything has internet.

Except my iPhone 5. Of course. It gets a signal fine (full bars). It gets an IP address. But I can't surf the web. Or download email. Or iMessages. Anything. No internet access. I try hard restarts on my iphone. I try assigning IP addresses by MAC address. I try resetting the AE. I try renaming the WiFi name. Nothing. I can make a guest network that works (on a different IP table, btw - 172, not 192.) But other than that, no access. Grrrr.

So I have a "working" AE router where some devices successfully connect (through wifi and ethernet) and some dont' (wifi iPhone). My iPhone connects fine to my home TC. So shouldn't be anything to do with that. But I'm at a loss. I'm going to go back and restore everything and power cycle everything tonight or tomorrow night. I don't know if that will help, but it's worth a try. Lord knows it feels like I've tried everything else.

Anyone have any good ideas of where to start besides voodoo dolls and baseball bats?