B250M-HDV PCI-e USB power off problem

Hello,

My B250M-HDV has a problem with the USB ports - not working, no power to them or at least I thing it is this. I have decided to buy expansion PCI-E USB card and use it, instead of m/b replacement or repair. The adapter is working perfect, but there is one major problem - PC is not turning off:
- when I shut down the PC from Windows, CPU fan is not stopping, there is power to the mouce/keyboard
- when I restart the machine from Windows - it stops/starts
- without PCI-e USB expansion card, simple turn-off, restarts are done very fast..
Seems that problem is with motherboard's BIOS firmware as I tested with different PCI-E cards, on other machines too. I have no option for Deep Sleap like other motherboards, to resolve the problem.

Please advise and thank you in advance!