A1243 keyboard doesn't wake up my MacPro

I have an older Mac Pro with an A1243 keyboard attached to it.

Works just fine.

I recently got another A1243 keyboard from the used market. All the keys work but none of the keys will wake up my Mac Pro. I have to click the mouse instead which is plugged into the USB port in the keyboard.

Went over the two and the only difference I spotted was that my original keyboard has these graphics on the F3 and F4 keys:

The one that doesn't wake the Mac has these graphics:

Anyone ever experience this?