I had that problem with a new box couple of days ago.
I just kept trying until it flashed properly.
It would go through the flash sequence and say done but when turned off and on stuck with boot on front display.
Sometimes the rear usb would not flash at all but side would.
Apollo 23 would do this but apollo 22 ibox safe versionn worked fine.
I think newer boxs have had something changed in production but I could be wrong.
I have 2 more new boxs to try with but it will be tomorrow night before I can try.