iPhone 13 iPhone 13 dropping cellular connection

[engbren]

I have an iPhone 13 which is covered by AppleCare+. Last week, I noticed that my cellular data connection was regularly showing as connected to 4g or 5g with strong signal bars but I could not use data in any app. Switching Airplane mode on/off would get cellular data working again for a period of time but between 1 hour and 4 hours later, the issue would reoccur. When data was working, I was also seeing slower than usual connections and testing using the Speedtest app showed very high packet loss between 67% - 94%.

The phone is setup with an eSIM, so I didn't think it would be the SIM but I contacted my carrier and they advised no issues from their end. So I went to the Apple Store and booked an appointment. The Genius ran tests on my phone in store, taking it out the back for a diagnostic scan of the modem inside a specialist machine he styled as a Faraday cage. The tests all came back working successfully but he could see in the cellular logs, the connection issue occurring regularly on my phone. He suggested that this could be a software problem with the baseband modem or a problem at the carrier end and I should do a network settings reset to reset the baseband software.

He said he would leave notes on my file and that if the issue reoccurs, I should contact chat and they would replace my phone. 2 hours later, I had the issue re-occur. I connected to chat where they said there were no notes. After several diagnostic conversations, the chat agent escalated me to a voice team member who "found the notes" and reviewed the tests undertaken at the Apple Store. He said, definitely this is a carrier issue and I should contact my carrier for a sim swap.

I contacted my carrier for a sim swap, which they sent to me but the new eSIM failed to activate. A day or so later my phone went to SOS mode and I got an email that my new eSIM was active but I could not activate it on my phone. I took the phone into my Carrier's store and got them to do a physical SIM swap. The new SIM was working when I left the store but I noticed that I never got connected to 5g even in areas where I previously had 5g coverage. It seems after the initial complaint to my carrier, they applied a network priority profile which locked my phone out of 5g service. I had that removed and again today, my phone data fails and I received 2 messages from customers that they were getting a message that my phone was switched off when they tried to call. I was in the office all day, connected to cellular data with full bars.

At this point I am back to thinking my phone modem appears to be failing intermittently and I need to book another Apple Store appointment and travel an hour into the city and back again to get this issue resolved. Its already caused me quite a lot of inconvenience, aside from missed calls, its meant I have had things like navigation stop working part way to an unfamiliar destination, been unable to contact my wife when I was picking her up after work from a train station etc. The whole experience so far has been frustrating and annoying and I am reminded of a similar scenario I had several years ago with an iPhone 5 that was dropping connection. In that instance, I took it to the same Apple Store, the Genius could see the issue was occurring through the logs and they replaced the phone on the spot.

 

[TriciaMacMillan]

I have similar issues with my iPhone 12 mini, but it’s only occasional, and I didn’t use to have them a while ago. I have a physical SIM, and the issues appear in certain places, for example, almost every time in a restaurant that I visit once a week. However, it always happens once, then my internet connection is gone for two or three minutes although I have three or four bars, then it comes back and usually stays connected for the rest of my stay. Therefore, my assumption was that it’s a provider problem, but now I’m starting to suspect an iOS problem.

 

[engbren]

My iPhone has a slightly different issue in that the connection doesn't come back up until I toggle airplane mode, or toggle cellular data off/on. It could well be another iOS 16 bug but I haven't seen widespread reports of it.

 

[TriciaMacMillan]

I also tried with toggling airplane mode, but my impression was that it didn’t make a noticeable difference. It still took a while after that too re-establish the internet connection.

 

[engbren]

I took my phone back to the Apple store and it was like groundhog day. After listening to my story, they ran the same tests and found my phone was working correctly, there was no hardware defect. The next step, according to them was to initiate a complete erase and setup the phone as a new iPhone. The test results indicating that there was a significant issue with cellular data from my last visit were not available and the notes from the last visit said no issue found with my phone and did not mention the constant cellular drops that were evident from the phone logs during the prior visit. As such, they refused to replace the phone. I asked about Apple Care and the express replacement service that is allegedly available to me and they stated that it only available if they detect a hardware fault.
They act as though their test suite is 100% perfect with no flaws. In the end, the best I could achieve was an agreement to send it to a depot where they can run a more complete diagnostic. They offered a loan phone while this process happens. An iPhone XR.. In these moments that matter that Apple used to absolutely step up and delight they are now failing. These moments will slowly turn those loyal to the brand away.

 

[one more]

I took my phone back to the Apple store and it was like groundhog day. After listening to my story, they ran the same tests and found my phone was working correctly, there was no hardware defect. The next step, according to them was to initiate a complete erase and setup the phone as a new iPhone. The test results indicating that there was a significant issue with cellular data from my last visit were not available and the notes from the last visit said no issue found with my phone and did not mention the constant cellular drops that were evident from the phone logs during the prior visit. As such, they refused to replace the phone. I asked about Apple Care and the express replacement service that is allegedly available to me and they stated that it only available if they detect a hardware fault.
They act as though their test suite is 100% perfect with no flaws. In the end, the best I could achieve was an agreement to send it to a depot where they can run a more complete diagnostic. They offered a loan phone while this process happens. An iPhone XR.. In these moments that matter that Apple used to absolutely step up and delight they are now failing. These moments will slowly turn those loyal to the brand away.

Considering the amount of distress it seems to be causing you, I would suggest you escalate it on the spot with either Apple or your carrier. However first you need to figure out the source of the problem. If you have another 5G iPhone in your surroundings, perhaps try putting your physical SIM into it and see if the issue repeats then?

If you suspect a carrier problem, get them to test your SIM card in front of you with another 5G iPhone, if you suspect your iPhone - ask Apple to test another iPhone 13 with your SIM card on the spot?

 

[engbren]

I have tested my SIM in my sons phone and it exhibited no issues. I suspect the phone.

 

[richard371]

Ive had this on the last 2 phones I have had 13 Pro max/14 Promax. All AT&T. Airplane mode on and off resolves it for X amount of time. On my 13 I had them switch me to a physical sim and it went away. Sadly it came back on the 14 max and there is no physical sim option. My coworker has the same issue. Annoying

 

[sorgo †]

Apple's software/firmware quality has been declining quite steadily especially over the last half-year or so, when the latter stages of any given software's development cycle should be seeing an opposite trajectory toward refinement and stability. It is no more apparent than in the subpar, flaky performance of base-level cell radios, across various device models (iPhone 13 mini for me, as well as on my dad's third-generation iPhone SE and on a friend's iPhone 11 Pro).

Both my father and friend reside on a rural island off the coast of northeastern Wisconsin in Lake Michigan; not exactly known to have great cell service altogether but the typical one to two bars should facilitate basic calling functionality and lately their devices haven't even been sustaining that. I on the other hand am in a populous urban hellhole with perhaps excessive cell coverage and have been experiencing with these most recent major iterations of iOS 16 (both beta and public) complete missed or dropped connections between tower(s) and device. Pathetic and frustrating.

So it's not just you, but always be prepared for the typical fanboy gaslighters to tell you you're holding it wrong or something.

 

[engbren]

Thanks @richard371 and @sorgo - good to know I'm not the only one experiencing the issue!

 

[engbren]

I got my phone back from the Apple Store today. Apparently they found an issue in the depot and have replaced the Rear System. It’s hard to get information on what the iPhone Rear System means but it seems to be logic board and battery as I see the battery health is back up to 100% and my phone has a new IMEI.

 

[richard371]

I got my phone back from the Apple Store today. Apparently they found an issue in the depot and have replaced the Rear System. It’s hard to get information on what the iPhone Rear System means but it seems to be logic board and battery as I see the battery health is back up to 100% and my phone has a new IMEI.

Did you have to reload everything?

 

[engbren]

Yes everything needed to be reloaded.

 

[engbren]

Unfortunately the repaired phone failed today. This time, the failure is worse - it goes to No Service and toggling airplane mode does not bring the mobile service back. Only a full reboot will bring mobile/cellular back and only for a short period of time.
The SIM works perfectly in other phones.

 

[engbren]

A bit of an update. After the repaired iPhone failed, I took it back to the Apple Store. The software on the iPad that the genius uses recommended another rear system replacement. I argued that the whole phone should be replaced and they agreed, so I now have the replacement unit. I've set it up as a new phone in case there was an issue with the restore of my old phones backup.
Even this new phone shows quite slow cellular connections relative to my son's iPhone 11. Even stranger is that high levels of packet loss still occur with the replacement unit when I am experiencing the slow page load times. I think there must be a modern firmware bug as I see between 35 and 98% packet loss when testing, and extremely slow uplink speeds in the range of 30-90kbps. I've reported it to Apple via the feedback app.
This new phone hasn't outright failed or entirely dropped cellular connections, it is getting high packet loss when other devices using the same SIM at the same location do not.