The thing is: The charger that sells FriendlyElec with the board is a copy of the Oneplus Dash charger and maybe for this charger to deliver all the power (nearly 4 amps) needs to have some negotiation between the load and the psu. As far as I know, the oneplus devices dont enter into this mode until something happens in the phone like 1 second after plugging in.
I don't think the charger is delivering this amount of amps but maybe 2'5.
I'll have to test it one of these days.
EDIT: Confirmed, the Dash charger from oneplus complies with a protocol for