Xperia 10 Plus shuts down after changing language from German to English/USA, is then unable to boot

Bug Reports
#1

REPRODUCIBILITY : 1x, but ever since not usable.
BUILD ID = OS VERSION: Sailfish OS 4.0.1.48 (Koli)
HARDWARE : Xperia 10 Plus Dual SIM,device i4213
UI LANGUAGE: German
REGRESSION: yes

DESCRIPTION:

Xperia 10 Plus shuts down without any warning after changing language from German to English/USA, and is hitherto unable to boot up again.

PRECONDITIONS:

  • Was trying to migrate the Signal account+profile from my previous Android 8.1 device to a fresh install of (Android-) Signal on my Xperia.

  • The direct transfer over WLAN failed with the german message:
    “Leider scheint dieses Gerät “Wi-Fi Direct” nicht zu unterstützen. Signal verwendet “Wi-Fi Direct” um dein altes Android-Gerät zu erkennen und zu verbinden. Du kannst jedoch stattdessen eine Datensicherung wiederherstellen, um das Konto deines alten Android-Geräts zu verwenden.”

STEPS TO REPRODUCE:

  1. Start with german language Setup,
  2. choose Settings, Language, EN (USA)

EXPECTED RESULT:

  • Aknowledged change and working on,

  • or at least a warning for the need of a reboot,

    • question like "Continue and reboot (yes/NO): "

ACTUAL RESULT:

  • immediate shutdown, no reboot.

  • I fear I should write: “Crashed System”.

ADDITIONAL INFORMATION:

Meanwhile hat to Reset To Factory.
Next time I would try to set to permanent Journal File 0n the mccard. (on the moment I have there only 3-4x backup.tar of /home/defaultuser and some app data.)