Asrock B450m Pro4 power on with keyboard

Hi.

I've recently bought the Asrock B450m Pro4 motherboard. I didn't want much from it, but one crucial feature I had a need for is the power on by keyboard/mouse functionality. This is because I have a custom build, and the PC is not located in the case, so I don't have a normal button to power it on.
Unfortunately, I haven't found anything that could help me to power on the PC with a wireless keyboard, or a regular USB keyboard, or a wireless mouse or a USB mouse.
The only thing that is present in the BIOS is Advanced -> ACPI Configuration -> PS/2 Keyboard S4/S5 Wakeup Support. However, I don't have and not willing to buy/use the PS/2 keyboard. Setting this option to "Enabled" did not make any effect with my USB keyboard. I have also tried to connect my wired USB keyboard into the PS/2 port through the adapter, and even though the keyboard is lighted up when attached this way, it is unable to power on the system.
On the other hand, I've tested my keyboard with some other regular Gigabyte motherboard, and it works perfectly well, powering on the system from any state, including after the full shutdown with plugging off the outlet. In the BIOS, I can even choose the button that would trigger the power on of the PC.

So before I return my Asrock motherboard to the store, I just wanted to ask the question here: is there something I am missing in the BIOS settings, or there's just no way to power on the PC using a USB keyboard/mouse?

Thank you.