Xperia 10 V loses SIM card?

REPRODUCIBILITY: Extremely weird
OS VERSION: 5.0.0.62
HARDWARE: Xperia 10 V XQ-DC54
UI LANGUAGE: English
REGRESSION:

DESCRIPTION:

The phone thinks no SIM card is inserted when it had it working perfectly a moment before.

PRECONDITIONS:

Fresh install after factory reset

STEPS TO REPRODUCE:

  1. Start phone.
  2. Log in.
  3. Test working OK
  4. A few moments later the network has dropped

EXPECTED RESULT:

To work normally like with Android.

ACTUAL RESULT:

SIM is gone and won’t come back.

MODIFICATIONS:

Factory Reset left the phone with Android 15, but install proceeded OK.

ADDITIONAL INFORMATION:

The truly absurd thing is that I had this exact same problem with the original Jolla phone. This is a decade later with a different phone, different SIM, different network operator, and the problem is back like it has been waiting for me. How is this even possible?