Adding the SteamVR addon camera prefab makes animations play slower

I'm building a simple Unity VR scene using a plugin to import MMD models and animations into Unity, but after setting everything up and replacing the generic camera with the SteamVR camera rig prefab from the SteamVR asset package my animations play slower than they're supposed to, even though the sounds and effects play fine. My project is just a simple scene with no scripts in it, so I'm not really sure what I would need to change or add. Does anyone have any ideas?