FMOD Audio not playing in HMD

So..weird issue. I am using FMOD. I installed the oculus plugin/dll for UE4 and added OculusSpatializerFMOD into the FMOD plugin settings. That seems to be working fine. The issue is that FMOD audio refuses to play on both my Rift and in a built package for the Quest 2. When I preview the app in VR, regular sounds are played over my Rift, but FMOD sounds are being piped into my attached USB Headset. It doesn't make much sense to me. On built packages on the quest, the FMOD sounds don't show up at all.  Any idea what's going on?