Additive Pose Asset arms become over exteneded when blended with reference pose

Asset is praising the sun rather than having his arms straight out to the sides when blended with the reference pose.

This is a regression from 4.14.3

1. Open QAGame
2. Open Test_Pose asset
3. Enable Additive and make sure Base Pose is set to Reference Pose
4. Click on the Apply button
5. Slide the Smile slider to 1.0

Result: Arms are raised above the head
Expected: Arms become parallel in a T-Pose