MacBook WiFi fast, iPhone WiFi slow using AirPort Extreme
I have a Verizon Fios modem/router combo, as well as an AirPort extreme. The modem/router has the wireless broadcast turned off (however it is still working as an ethernet switch), and the AirPort Extreme is plugged into that and set to "Bridge Mode." I have my 5GHz network setup, and both my brand new MacBook Pro and iPhone 5 are connected to that network. We pay for 50 Mbps download, and 35 Mbps upload speed from Verizon Fios.
I'm literally sitting three feet away from my AirPort Extreme, and when I run a speed test on my MacBook, I get a very fast download and upload speed with low latency. However, when I run a speed test on my iPhone 5 while sitting in the exact same place on the exact same network, I get extremely high latency, atrociously slow download speed, but an upload speed that's not half bad. The same happens on the 2.4GHz network from the same router.
I'm not sure if my iPhone is malfunctioning, or if my AirPort Extreme has anything to do with it, but we seem to have to same problem on all the Apple mobile devices in the house (four iPhones). All the laptops (a new MacBook Pro and a few 5GHz capable PCs) seem to work just fine on the network.
I know AT&T (my phone carrier, not ISP) updated their carrier settings about two weeks ago, and that's when we started noticing problems, but I don't feel like carrier settings would affect the WiFi. The problem must be with something on all the iPhone because it's happening to only the iPhones. So my question is, is there any known problem with the networking on iPhones currently, specifically the iPhone 5? If so, is there a way to fix it?
For anyone wondering, the first screenshot is taken from my MacBook Pro running Windows 8 in Bootcamp (so I can play games), and the second screenshot is taken from my iPhone 5.
AirPort Extreme-OTHER