Mine had the same behavior, the whole time I was running off of 4S LiFePO4, with Batt Full set to 13.200 and Step set to 0.233. Ever since I switched to 3S Li-Ion, with Batt Full set to 12.600 and Step set to 0.550, the battery indicator works as expected. Maybe this bug has something to do with the battery Red/Green threshold on 12.5V in the diagnostics menu.
