Windows 11. Connect Pro Micro to a USB-C port on the laptop. It does not show up in Device Manager. I tried a couple of different USB-C to USB-C cables, but the first one I tried listed on Amazon says “High-Speed Data Transfer: Transfer files quickly with 480Mbps data transfer speeds” so it’s not a charging only cable.
AND, I can use a USB-C to USB Mini adapter connected to one end of the cable and connect to an Arduino Nano and it works fine.
So I used a USB-A to USB-C cable, and can connect to the Pro Micro just fine that way.
Curious.
So I worked around this, but just wondered what the heck could be going on.
Odd, I’d wonder if the cable is outputting the full 5v…can you probe its pins?
Tried 3 different USB C to USB C cables. Measuring no voltage at RAW or VCC. As mentioned, when I add an adapter (USB C to USB Mini) to one end it will power an Arduino Nano with no problem, and voltage measures 4.9V.
It seems to have something to do with the fancy smart voltage switching capabilities of USB C.
I was assuming they were used on different ports, apologies
The mentioned newfangled power negotiation usually wants a full 5v
If it doesn’t suit your use-case we can sort 
it out