Cannot get Wii U GameCube Adapters Working

I have come across one of those Wii U GameCube Adapters which I am trying to get working with Lakka, so far with little success. The adapter has the following info on it:

GC Controller Adapter

For SWITCH/WII U/PC

ITEM TO: HS-W025

I have followed these instructions:

https://www.lakka.tv/doc/Wii-U-GameCube-Adapter/

The adapter also has a switch for WII U and PC, I have tried it in both positions. So far nothing has worked, none of the controller’s buttons, d-pad, or analogs seem to be doing anything.

Any suggestions on how to try to troubleshoot this? Are there logs or tests I could do to further investigate this. Or am I simply out of luck?

Also, I currently have Lakka installed on an older X86_64 PC.

Thank you