This problem has persisted, I've had a few times where the system would not boot fully. Each time, I've re-flashed the SD card and setup everything again.
Tonight it has happened once more, no pattern to it. At power-on the boot screen appears with the progress bar. The progress goes full speed to 3/4 of the way through, the final 1/4th becomes ever slower, after 5 minutes it completes and says "AMIGA KIT", but progresses no further.