Hallo,
the bootloader is unlocked becouse when I locked the bootloader with 2.3, I get the error that my Fairphone is corrupt and the phone will not boot.
So, I left the bootloader unlocked and the Fairphone will boot.
I have installed Iode OS 2.4 Beta desciped here
iodéOS 2.4 beta available (I have used the UpdaterIodeBetaAndroid11ToAndroid11V2.apk)
With Iode OS 2.4 Beta I can lock the bootloader and the Fairphone boots.
I have tested to unlock and lock the bootloader again and it worked.