Fresh installation of 184.108.40.206 on Xperia 10 iii.
This is a modal problem and last time it was triggered by a hard reset.
The initial PIN check doesn’t resolve ~80% of the time. The circular wait graphic repeats forever.
Breaking the cycle by going into the Recovery menu and powering off before cold resetting works 3 for 3 times so far. I suspect the failure of flash procedure to properly finish is the cause.
[Moved from General]