iPhone 13 display turns on and SIM connection drops during the night after iOS 26 update

Device: iPhone 13

iOS version: Latest iOS 26.1 (23B85)

SIM: Physical SIM


1) Display turns on during the night

Issue:


In the mornings I often find the screen turned on, showing the Lock Screen, even though:

  • no alarm is set,
  • no notifications arrived,
  • and the phone was not touched.

It doesn't appear until I press the close button.

This never happened before updating to iOS 26.


2) SIM connection drops during the night

Issue:

Sometimes I wake up to a prompt asking for my SIM PIN, because the phone lost connection to the physical SIM card overnight.

This also only started after updating to iOS 26.

Frequency:

One of these issues occurs roughly every 2–3 nights.


Expected behaviour:

  • The display should not turn on without any trigger.
  • The phone should not lose the physical SIM connection or require the PIN unexpectedly.


[Re-Titled by Moderator]

Original Title: iPhone

iPhone 13, iOS 26

Posted on Dec 2, 2025 12:26 AM

Reply
3 replies

Dec 2, 2025 5:25 AM in response to Mrkgabor

Mrkgabor wrote:

Device: iPhone 13
iOS version: Latest iOS 26.1 (23B85)
SIM: Physical SIM

1) Display turns on during the night
Issue:

In the mornings I often find the screen turned on, showing the Lock Screen, even though:
no alarm is set,
• no notifications arrived,
• and the phone was not touched.
It doesn't appear until I press the close button.
This never happened before updating to iOS 26.

2) SIM connection drops during the night
Issue:
Sometimes I wake up to a prompt asking for my SIM PIN, because the phone lost connection to the physical SIM card overnight.
This also only started after updating to iOS 26.
Frequency:
One of these issues occurs roughly every 2–3 nights.

Expected behaviour:
The display should not turn on without any trigger.
• The phone should not lose the physical SIM connection or require the PIN unexpectedly.

[Re-Titled by Moderator]
Original Title: iPhone

This is a known bug, we're not sure if it will be fixed any time soon.

In the mean time the current advice is to turn off the SIM PIN lock. This will avoid missed calls!

Longer term fix is to go to eSiM which does not need to be locked.

Dec 2, 2025 4:57 AM in response to Mrkgabor

It's not always the iOS update's fault!  Many things can cause phone problems.  If you tell people you think it's an iOS update, it might make it harder to fix or find a solution for the real issue.



Remember, the right question often leads to the solution!



Was/Is your device Jailbroken? If that's the situation, please be informed that attributing the issues to iOS updates may not be accurate.



iOS updates aim to enhance user experience, boost security, and fix bugs rather than disrupt core features. The majority of the issues after updates might stem from underlying, unmentioned factors. Updates won't typically alter personal data but may refine settings or features. Backup before major updates for safety. Review Apple's update details and backup advice for a smooth process.


Kindly consider checking your settings and addressing any device issues before attributing the issue to external factors. This could be a pure coincidence that the iOS update affected the iPhone functions.


Before initiating a standard iOS update, it's advisable to create a backup. Have you completed this step? If yes, proceed with the restoration from the backup.



See what each update does: OS — iOS 26, About iOS 18 Updates, About iOS 17 Updates, About iOS 16 Updates, About iOS 15 Updates, About iOS 14 Updates, About iOS 13 Updates, About iOS 12 Updates, and so on...


Dec 2, 2025 4:58 AM in response to Mrkgabor

If you see No Service or Searching on your iPhone or iPad

  1. Check your coverage area. Make sure that you're in an area with cellular network coverage. ... 
  2. Restart your iPhone or iPad. Restart your device. ... 
  3. Check for a Carrier Settings update. ... 
  4. Take out the SIM card. ... 
  5. Reset your Network Settings. ... 
  6. Update your iPhone or iPad. ... 
  7. Contact your carrier. ... 
  8. Get more help.


If you see No Service or Searching on your iPhone or iPad ...



Remove your SIM card from the SIM card tray and then put the SIM card back. ... Make sure that the SIM tray closes completely and isn't loose. If you use a SIM tray from a different model iPhone, iPad, or from another phone manufacturer, it might not fit properly.


If you see 'invalid SIM' or 'no SIM' on your iPhone or iPad ...



Learn what to do if you see a SIM not supported alert.



If you see No Service, Searching, or SOS on your iPhone or iPad

  1. Check your coverage area. ... 
  2. If you see SOS or SOS only. ... 
  3. If you're on 3G network. ... 
  4. Restart your iPhone or iPad. ... 
  5. Check for a Carrier Settings update. ... 
  6. Turn your cellular line off and back on. ... 
  7. Reset your Network Settings. ... 
  8. Update your iPhone or iPad.

More items...


If you see No Service, Searching, or SOS on your iPhone or iPad



To be able to use any SIM across the globe you must have "No SIM Restriction" against Network Provider Lock. Please refer to the pic below.




If you see No Service or Searching in the status bar on your iPhone or iPad (Wi-Fi + Cellular), your device isn't connected to a cellular network. If you see SOS or "SOS only" in the status bar, your device can still make emergency calls.


If you see No Service, Searching, or SOS on your iPhone or iPad

iPhone 13 display turns on and SIM connection drops during the night after iOS 26 update

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