Layer with no RM overrides RM on Base Layer. This works as expected in 5.6

I have a Base Layer with full body Humanoid animation and Root Motion applied to the character.
I have a second Layer with only a BlendShape animation on the face (eye blink) of the character.
When the second layer has no weight, the base layer root motion is applied as expected.
When the second layer has weight, the base layer root motion is no longer applied... bug.

repro:
-open FaceNmotionTest scene
-Play the scene
-with the face layer weight at 0, the character moves as expected.
-with the face layer weight at more than 0, the character no longer has root motion... bug!

this is a regression
repro in...
Version 2017.1.0f3 (02b68a5193da)
Branch: 2017.1/staging

not repro in...
Version 5.6.2p1 (8a29de46e0a0)
Branch: 5.6/patch-release