I have the same problem. spent 2 days to migrate my project from UE 4.16 to 4.18. and still can’t find the right mapping. all the buttons are correctly mapped but I still can not map touch/tap either on motion controller or HMD touch pad. it was MotionController_Left/Right_FaceButton6 or touch1. also for touch detection like MotionController_Left/Right_Thumbstick_X is still blurry.