Hello, i need help,

I'm using an Asus B250 Mining Expert, using 13 RX 580.
It works very well, around 360 Mh/s in ETH.
The problem is when I need to restart the system, each vga back mining at 1 Mh/s with a total of 13 Mh/s.
No matter how many times I restart the system, it always gets 13 Mh/s.
It only works again when I turn off the key of all the power supplies and I call again.
Does anyone know how to solve it?
Sorry for my bad english.