Missed phone calls when in dual sim on iPhone 11

Question

Level 1

7 points

Missed phone calls when in dual sim on iPhone 11

Hello, I use two sim :

SIM 1 (phisical) >> Work

SIM 2 (E-Sim) >> Personal

Since I switched to iPhone 11 I experienced some problems when both sim were on. Many customers reported me that line was busy even if it was free and both lines had 4-5 bars of signal.

I thought there was a problem with my operator (TIM) and this year a switched to the best operator in my area (Vodafone) but the story does not change...

I continue receiving many messages reporting that Number xxxxxxxxxx has called me when I was busy ... but I was not !! Also got customer that tell me my phone was busy when It was not.

I tried to switch off SIM2 (personal) and the problem disappeared... so it looks like the two SIM have a conflict.

Is there a way I can solve this problem ?? Is this problem known and has it been solved in further iPhone models ( iPhone 11 is the first dual sim in Europe... so maybe it is a sin of youth !! )

Thank you all and sorry for my basic English.

iPhone 11

Posted on Jan 27, 2023 3:51 AM

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Answer 1

SnickZ.

Community Specialist

Jan 30, 2023 8:27 AM in response to GGEECC

Hello GGEECC,

You stated that this is an issue 100% of the time. Given that there is never a time that the SIM cards work together what we’re wondering is which number is set as the primary and if changing that has an impact. Also, are both SIMs through the same carrier or are we working with two different carriers?

When this happens are you having any issues making outbound calls on the same line? Lastly, please be sure we’re working with iOS 16.3 on your iPhone. If you need assistance installing any updates, here’s how - Update your iPhone or iPad

Update your iPhone or iPad wirelessly

1. Back up your device using iCloud or your computer.

2. Plug your device into power and connect to the internet with Wi-Fi.

3. Go to Settings > General, then tap Software Update.

4. If you see more than one software update option available, choose the one that you want to install.

5. Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.

Thanks.

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Answer 2

ManJor

Community Specialist

Jan 30, 2023 11:53 AM in response to GGEECC

Hello GGEECC,

Can you finish updating and let us know if it helps? Some issues can be resolved by the updates.

Cheers!

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Answer 3

Jan 29, 2023 1:33 PM in response to GGEECC

Hello GGEECC,

Please check out the following link to ensure Dual SIM is set up correctly, so we can make sure there's no issue there: Using Dual SIM with an eSIM

How can you use Dual SIM?

• Use one number for business and another number for personal calls.

• Add a local data plan when you travel outside of the country or region.

• Have separate voice and data plans.

Both your phone numbers can make and receive voice and FaceTime calls and send and receive messages using iMessage, SMS, and MMS.2 Your iPhone can use one cellular data network at a time.

If you want to use 5G with Dual SIM on iPhone 12, iPhone 12 mini, iPhone 12 Pro, or iPhone 12 Pro Max, make sure that you have iOS 14.5 or later.

If Dual SIM isn't working as expected, please also check out the details in this link, which can help correct several Dual SIM issues: If Dual SIM with eSIM isn't working on your iPhone

If you need further assistance, please contact Apple Support for help. You may be able to reach them here: Contact Apple Support

Thanks!

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Answer 4

GGEECC Author

Level 1

7 points

Jan 30, 2023 11:33 AM in response to SnickZ.

Hello and thanks for your answer. I shold have explained better !!

I mean "they do not proprely work togheter 100% of times" as they should do ... so I confirm I regulary receive calls on both lines when both sim are active. But some times ( let's say 1-2 calls on 10 ) customers calling find work line busy or not available even if line is free and with 5 bars signal.

If I do disable personal SIM ( Esim ) this problem ends and I receive all calls regulary.

SnickZ. wrote:

Given that there is never a time that the SIM cards work together what we’re wondering is which number is set as the primary and if changing that has an impact. Also, are both SIMs through the same carrier or are we working with two different carriers?

SIM 1 (phisical) >> Work

SIM 2 (E-Sim) >> Personal

Work number is primary and with phisical SIM , I cannot swap them since I shoould change my E-sim to phisical and viceversa.

I confirm you I use two different carriers, before december :

SIM 1 (phisical) >> Work >> TIM ( national italian carrier )

SIM 2 (E-Sim) >> Personal >> WIND

then in december I tried changing carrier to check if this could solve this problem but it didn't , so actually is :

SIM 1 (phisical) >> Work >> VODAFONE

SIM 2 (E-Sim) >> Personal >> WIND

When this happens are you having any issues making outbound calls on the same line?

No, don't have particular problems on outbound calls... ( it could have been happened sometime but I suppose this is related to carrier connection )

I keep my phone updated... actually is IOS 16.2 but I'm upgrading 16.3 right now.

Let me know !

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Answer 5

Chris_C1

Community Specialist

Jan 31, 2023 11:06 AM in response to GGEECC

Hey there GGEECC,

At this point, you'll want to Contact Apple Support for assistance.

Have a good one!

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Answer 6

GGEECC Author

Level 1

7 points

Jan 30, 2023 1:23 AM in response to Brittany1416

Hello Brittany, thank you for your response. I checked links you posted but I can confirm you that Dual SIM are correctly set, and they do the work as expected, but as I explained above they do not proprely work togheter 100% of times.

Since it's long time I need dual sim I always owned Android smartphone and nevere had this kind of problem. As soon as Iphone relased a dual Sim phone I switched to it... but it's kind weird that the most advanced (and expensive ) cell phone on the market has these kind of problems on the most basic task PHONE CALLS !!!!

Thats even really serious since I'm missing calls for potential customer.

I should really solve this .. I 'm available to upgrade my Iphone but I need to be sure that further models do not have the same problem.

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Answer 7

GGEECC Author

Level 1

7 points

Jan 31, 2023 10:53 AM in response to UTBadger

Hello ...I upgrade to the latest IOS 16.3 yesterday evening. Today I kept both SIM active, and I received a 3/4 SMS for missed calls ( as I were not available or busy ... )

Few minutes ago my phone was free, I was not calling, 5 bars on my mail line... a customer send me a mail telling me that he tried calling me but the line was mute and he didn't even ear ringing. In the mean time I received a SMS stating that XX XX XX called while I was busy or unavailable....

So upgrading didn't solved problem.

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