Can't switch surface material sounds with Wwise and Unity using Box Collider and Ak Switches.

Question

Can anyone help me troubleshoot this issue? Forgive my lack of knowledge on this subject. I have followed various tutorials on how to switch footstep surface sounds using Box Colliders and Ak Switch. Testing switches in Wwise transport works fine. I have the Box Collider set to is trigger with an Ak Switch Script component attached set to AkTriggerEnter and Use Other Object with Footstep_Material Gravel chosen from the drop down list.

I've tried everything I can think of but I can't figure out what i'm doing wrong. I did manage to get an empty object to set the switch to gravel in Wwise but the sound stays on default of concrete. I can provide further information on request. Any help would be much appreciated.