I found a solution on the Unreal Forums. In your Tracker Blueprint, place a CombineRotators node in between your Get Tracked Device Position and Orientation node (or GetWorldRotation node) and the SetRelativeLocationAndRotation (or SetRelativeRotation. Plug the return value from the Get node into the B input of the CombineRotators. set the A values as: X = 0, Y = 90, z = 0. Here's the link to the forum thread...
Vive Tracker in Unreal
in VIVE & VIVE Pro
Posted
I found a solution on the Unreal Forums. In your Tracker Blueprint, place a CombineRotators node in between your Get Tracked Device Position and Orientation node (or GetWorldRotation node) and the SetRelativeLocationAndRotation (or SetRelativeRotation. Plug the return value from the Get node into the B input of the CombineRotators. set the A values as: X = 0, Y = 90, z = 0. Here's the link to the forum thread...
https://answers.unrealengine.com/questions/744900/htc-vive-tracker-in-unreal.html