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iOS 11 4G isn’t working

Not applicable

I’ve updated my phone to iOS 11 and ever since I haven’t been able to get 4G? It’s an iPhone SE. The battery drains really quickly too but I can deal with that. Would be nice to have faster internet speeds when not on WiFi!!

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Not applicable
Have you tried a factory reset?

This link may help
Message 2 of 5

Level 94: Supreme
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Wipe phone completely and restore from an iCloud backup, that way you won’t restore any system settings which may be the cause of the issue.
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion. This is not Customer Service so we are unable to help with account specific issues.

Currently using:
OnePlus 6 (O2 & Sfr), Z3 Tablet (Three UK), iPhone 8+ (EE)
Message 3 of 5

Level 28: Ingenious
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@Anonymous couple of things you can do before resetting.


check with o2 that you are on the correct iPhone data bundle tariff. 



Next reset the network settings.

settings> general> reset> reset network settings.

note this will also loose any stored Wi-fi or Bluetooth devices pre stored.



you can check if 4G is still on

Settings> mobile data> mobile data options> enable 4G> in there you can choose data or data and voice ( this being for if you enable Wi-fi and 4G calling]



or you can reset the data mobile data settings it self.

Settings> mobile data> mobile data options> Mobile data network: scroll to the bottom and then click reset and then reboot your device.



Also check the area on o2 coverage for any outages and if you have another device, try the sim in that and see if you get 4G, ( if it’s a 4G device) on that too.


other that the above, its a reset as others have said.


regarding the Battery drain, Apple are aware of this and IOS 11.1 should resolve this issue which is due out shortly.  There is plenty of news regarding battery deprecating quickly in IOS 11.0.x.


just go to Goold and type it in.  But developers any many people including myself have confirmed that the battery is better using IOS 11.1. I’ve tested it my self using the test IOS 11.1 beta 5 and battery life has improved on IPhone 7 and SE that was tested on.  Also IPad Pro 10.5 is handling battery better too.


hope this helps and good luck.


donlet us know what happens. 



Need Help, Just ask. We are one big Family here in the o2 Forum.
Use iPhone XS Max dual sim, SE, Honor 10, IPad Pro 11, Apple Watch 4 LTE, 100+ Mpbs Barrier and a Record Player.

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Former Staff
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Good morning @Anonymous! Welcome to our forum! Lots of helpful information above from our helpful members, did any of it resolve the 4G issue on your phone? Please let us know how you're getting on.


Cheers @Anonymous, @MI5 and @darrengf for your help! thumbsup

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