Issue with Multi-Aim constraint

I'm currently unable to have my character's head aim at a target, no matter how much I tweak the aim axis. My character was exported from Blender (fbx) with Y-forward and Z-up, and then I added the bake axis conversion option in Unity.

Not sure if this is helpful: Currently, the head bone has the local Y-axis pointing behind the head (z points up, x points to the character's right). I've been trying using -Y as the aim axis to no avail.

Thank you,
Pedro

 

head is rotating wrong or not rotating at all?