I finished my game this morning in Unity and I tested everything with my HTC Vive. When I sent my game to one of my friends so he could test it, he used a Valve Index and couldn't get his controllers to work!
I have OpenXR enabled on my XR Plugin Manager and both Vive's and Index's controller profiles enabled. I'm also using version 2020.2.1f1
Have any idea of what could be the problem? In the worst case scenario, I think my game will need to be played exclusively on an HTC Vive :(