computer keeps restarting after shutdown

i have the asrock b450m hdv r4.0.

the usb ports keeps the keyboard mouse lights on even after shut down .
to overcome this i performed below changes
1. disabled fast startup
2. disabled all peripherals from waking my computer
3. and finally changed deep sleep option in bios to enabled tried S5 and S4 & S5 .

strangely after enabling option 3 , i cannot turn off my computer. everytime i attempt to shutdown, the computer keeps restarting..
i finally had to disable deep sleep and then the computer doesnt restart automatically.

now what i want is to completely disable power to usb ports. is there any other worknaround£
also any idea why enabling deep sleep makes the computer restart,

thanks in advance

thanks, will this delete all customization? i.e. my userprofile setup such as ram settings, boot preference etc..