PROBLEM
I have a very strange problem: my iPhone network seems to hang every few minutes. It happens in Safari, Mail, News, Twitter, Tweetbot, YouTube, and other apps. Here are some ways it happens:
- when I Google search from the Safari omnibar (page load progress bar gets stuck at 15%, network activity spinner keeps spinning, followed often by a "Safari could not open the page because the server stopped responding"; oddly, Google autocomplete suggestions work perfectly while I'm typing the search query)
- when I click a link in the search results (the page load progress bar gets stuck at about 30%)
- when I try to refresh Mail with pull-down and release (the "Checking for new mail" message shows for a long time, even though my mail server is on the same LAN)
- when I click on a story in News (blank page often followed by "you're not connected to the Internet")
- when I click on a link in Twitter or Tweetbot
In all instances, I just have to wait a minute and everything is back to normal, until it happens again in 5-10 minutes, which is super annoying.
I have multiple wired and wireless devices connected to the network (and AirPort Extreme 802.11ac wifi access point) and this only happens on my iPhone. I don't think I'm losing wifi during these hangs, I suspect it's some kind of TCP/IP (DNS, IPv6, etc.) issue. I have an uncommon network setup:
Internet > cable modem > pfSense firewall > Windows Server (Mail and DNS server) > LAN switch > Airport Extreme
QUESTION
What is causing this?
What do I look for when debugging this using the Device Console, Xcode Instruments, or WireShark?