Client machines using Apple iOS, such as iPhones and iPads, are not able to update their OS.
iOS updates are getting blocked by the app control signature HTTP Proxy -- Proxy Request (SID 7300)
If you want the signature not to be blocked for a short period of time:

CAUTION: This completely Disables App Control for the whole firewall and connections until you re-enable it.
To keep App Control Advanced permanently enabled and if the updates need to be allowed permanently,
you will need to disable this specific signature ID 7300:

