Gamecube adapter not detected on B350 motherboards running Windows 7
Title explains it, the official and Mayflash Nintendo Gamecube adapter are not detected when using Dolphin emulator running Windows 7. This was fixed with X470 motherboards, don't know about B450 but if AMD could backport this to Ryzen 1st generation motherboards that would be great, and I know Windows 7 is reaching end of life but it would be great if this could get fixed. Here are some references on the topic:
It is very unlikely anyone from driver development will see your request here. These are User to User forums. I would send your request through a support ticket: Online Service Request | AMD