Of course it is since it's limited to 5V/2A (10W) and that's not sufficient for a board that needs up to 5V/3A. The only real measurements I've seen so far speak about 3A when the board is used with common peripherals under full load: http://linux-sunxi.org/Banana_Pi_M3#Sudden_shut_offs_.2F_maximum_consumption_.2F_cooling_vs._consumption
And the other problem is that the micro USB connector let people try to use the most crappy phone chargers ever to power their device. That might work on devices that do not consume that much (Raspberry Pi, Banana Pi M1/M1+ or the cell phones the chargers were bought for) but not with the power-hungry M3.
Anyway: Given this lousy decision, the slow USB-to-SATA bridge, all the broken OS images (why not just one that works instead of many that all suck in one way or the other?) and the non-existent support situation it's clear now what to do: Avoid the M3 and close the account here.