After updating to iOS 15.6.1 I have mobile data problems:

  • Sometimes the network is unreachable
  • Sometimes the network is slow
  • Sometimes 4G is unavailable and only 2.5G is available

It's just unreliable. It could be that I miss a whatsapp call, or that during the call I can't hear anything for a few minutes and the call disconnects, or that I can't load a web page. I also have problems with regular phone calls and messages. Once it happened that out of 8 attempts to send an SMS, the first 7 failed.

I contacted my carrier and I made sure that the phone settings are correct, and I asked many people who have my same carrier and also tried to use another person's SIM card on my phone with another provider. I can conclude that the problem is in my phone, most likely because I upgraded to iOS 15.6.1.

I tried many things like:

  • iPhone factory reset
  • Restarting my phone
  • Turning on/off airplane mode
  • Resetting network settings
  • Re-inserting my SIM card

Among many others. The above fixes can sometimes temporarily solve the problem, but then it pops up again! It's unthinkable for me to use my phone like that, I am supposed to continuously restart it or play around with my settings before using internet. Not to mention the fact that while I am outside I can miss calls.

What astonishes me is that it's not possible to downgrade to iOS 15.5 because the IPSW file is not signed by Apple anymore (I tried on ipsw.me).

What to do? For me it's unthinkable to use my phone like that, like if I was in the 80's. Does anyone have a solution?

PS: I am using an iPhone 11.

  • Have you tried someone else's sim card in your phone? This is a very unlikely reason for have connectivity issues.
    – Ezekiel
    Sep 7, 2022 at 18:38

1 Answer 1


There is no viable path to downgrade, so you’ll need to work through the quick fixes like resetting network settings and then work via support to narrow down a fix if any.

For what it’s worth, I have that same model phone and it’s working well with my mobile carrier in USA. I seem to need or want to reset the network every 10 months, so that can help clear up carrier capabilities and cell tower databases.

If it’s not software or configuration, the update may be coincidence and the antenna or amplifier needs a repair once you e ruled out software or carrier issues.

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