A phone or tablet problem starting right after an OS update, a new case/accessory or a restored backup should be checked against that change first. For iPhone eSIM or cellular line, first check Settings for the line status and test the carrier QR/app on stable Wi-Fi.
What this covers
- iPhone eSIM or cellular line with this exact failure state
- Diagnosis across carrier provisioning versus device lock, line selection and activation network
What it does not cover
Try in this order
0 of 4 completedCapture the exact failure state
ReversibleNote the exact update version, accessory or backup date, and confirm the feature worked immediately before it. Expected behavior: activate the intended carrier plan and remain selected for calls, texts and data.
Isolate the component boundary
ReversibleCheck Settings for the line status and test the carrier QR/app on stable Wi-Fi. Test with the new accessory removed, or check the update's known-issues note for the exact symptom. Boundary to separate: carrier provisioning versus device lock, line selection and activation network.
Correct only the proven cause
ReversibleHave the carrier reissue provisioning or correct the default voice/data line. Reset the one setting the update changed, or replace the incompatible accessory.
Verify and stop safely
ReversibleConfirm normal operation with the change present for one full day of typical use. Do not delete the only eSIM until the carrier confirms a replacement activation path.
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