Power button not starting the UP board!

biscuit

I‘m having the following problem with the regular up board (4gb 64gb) using the 5v6a power supply (intended for up2) and win10pro:
The powerswitch does not turn on the board. The board does boot up immediately when the power supply is connected and i can shut it down with a single press on the power button, but the same button does not boot it up again. Only way i could find is to disconnect and reconnect the power supply.
Is that normal behavior? How can i make the power button turn on the up?

DCleri

Can you try to hold the button until the blue led will be on?

Then the board should power up correctly