That mysterious iOS 17.2.1 update released just before Christmas seems to be causing havoc for some iPhone users.

A couple of readers pointed me to a thread over on Apple's support forum where users are complaining of having problems connecting to their cellular network following the update.

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The problem seems to affect calls and data, and while the majority of complaints appear to be from T-Mobile and Verizon customers, the problem doesn't seem limited to these networks. 

Forum users have offered up a few suggestions, ranging from deleting any VPN profiles off the iPhone (tapSettings > General > VPN & Device Management > VPN, then tap thei next to any VPN profiles and Delete VPN) to resetting network settings (tapSettings > General > Transfer or Reset iPhone > Resetand then tapReset Network Settings), but these have had limited success, and I believe that these are solving secondary issues, not the issue being caused by the update.

And the majority of affected users don't have a VPN installed.

Bottom line: These are worth a try, but don't hold your breath.

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It's also worth noting that this issue isn't new; I've seen sporadic reports for this on many prior updates. However, this specific iOS 17.2.1 update seems to be creating more widespread issues.

Along with this cellular issue, some users are claiming that the update has adversely affected battery life, while others are claiming that the iPhone overheating issue is back. 

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