Continuous proxy popup since 11.2.2

We have several iPads that have been in production for several months using a wireless profile configured via AirWatch. The network uses a PSK (WPA2 Personal) and the proxy credentials are also configured within the profile. Ever since updating to 11.2.2, our users will get the Proxy Authentication Required constantly. Clicking cancel three times will eventually make it go away temporarily. I've tried different proxy servers and user accounts to no avail. 11.2.5 did not fix the issue.

No changes have been made to our firewall or the SSID being connected to. Happening on iPads, iTouch, and Iphone.