Intermittent ‘No Internet Connection’ Issues on Apple Devices in Corporate Network

It sounds like your suspicion could be on point! When Apple devices connect to the internet, they often use Captive Portal Detection, which sends specific HTTP or HTTPS requests to verify connectivity. If your firewall blocks these requests, or if any SSL inspection alters the packets, the device won’t get the expected response, prompting the "No Internet Connection Available" error. You might want to check your firewall settings—some have features to bypass Apple detection specifically. Also, be cautious of SSL inspection settings—they can lead to many connectivity headaches too.

Are these devices personally owned or company-issued? If some are personal, the policies could vary. Just to clarify, you're in IT, right? Given the setup, I wonder if the firewall might be configured to block certain connections for security reasons, and that could explain the intermittent issues. Have you been able to check for any recent changes to the firewall or access point configurations?

One thing to consider is whether your access points are set to automatically select channels. Sometimes, if they switch too frequently, it can cause compatibility issues that disrupt connectivity. I know you mentioned a fix was applied for that, but it's worth verifying again, just to rule it out since signal stability is key for these devices.