1. You need 3 people. Join on the same world.
2. "Hide Avatar" on one user. 1. Leave the other one alone (Our case had the user on "Use Safety Settings")
3. Drop a portal to another world. All three enter the portal.
4. When you load into the new world, the avatar-hidden user should still have their avatar hiding.
5. Observe the not-hidden person as they locomote/move around.
The not-hidden person acts normally and has IK/locomotion animations.
The not-hidden person is stuck in an idle pose and slides around when locomoting. If they are in VR, they are still stuck in that pose.