How to reproduce:
1. Open the attached project
2. Open and play blitzer scene
3. Notice that the model is going downward instead of staying on top of the ground plane
4. Select the model and disable Apply Root Motion in the inspector
5. Play again and notice that now it stays on the plane

In the animation file the "Movement" bone has a translation along the y-axis (see the attached screenshots) that should result in a forward movement inside unity.
It seems that unity do not convert z-up model to y-up model when computing the root motion.

Workaround: If root motion is handled by script and localRotation is affected that would prevent from the issue.