Hi all,
before my answer The whole process depends on your personal situation, so when you migrate to /e/ and which Android Version was installed before you start the process! You need to check the security patch level of the Android Version from Fairphone against the one provided by /e/.
In my case, i installed the latest Android version provided by Fairphone early March and migrated the FP4 only a few hours afterwards, which was not the best idea as we know today. The /e/ version i used, had therefore an older security patch level than the latest Fairphone standard Android release for the FP4. Now e-0-23 was provided with an updated Android security patch level and therefore i was able to lock the bootloader again.
So it was like that
- 4.March i got my FP4 as standard Fairphone modell
- 6.March - installation of FP4 standard Android update => security patch level Feb 22
- 6.March - now I migrated to /e/, using 0-21 => security patch level is old, most likely Jan 22
=> boot loop when locking the bootloader - Late March - install e-0-22 = security ptach level still Jan 22 => still too old
- 21.Apr - install OTA update e-0-23, having March security patches
=> now i tried and was successful, locking the bootloader
I installed the 0-23 as normal OTA, NOT a fresh install! Just with that update nothing was deleted oir wiped!
Afterwards i booted into fastboot again and locked the bootloader. Because of that locking of the bootloader the phone got wiped.
I hope that explains the process.