I bought an old skool gamecube to USB adapter. I updated it using zadig the way dolphin recommends on its site. When I plug the adapter into my PC directly, dolphin sees the gamecube controller with no problem.

When I pass the adapter through my steam link, dolphin doesn't see the adapter. Virtualhere sees the adapter and says it's being used. Looking through steam settings, a new controller named Betop BFM Gamepad shows up. When I try to disable steam input, dolphin still won't see the adapter.