This is a regression from release 4.21.2
Motion controller meshes are present in the level, they just aren't tracking alongside the motion controls.
Motion controls still function as intended otherwise.
Regression:
//UE4/Main
//UE4/Dev-VR
Required - Vive or Oculus Rift with motion controllers setup with latest run-times
Results: Motion Controller meshes will be locked at the origin point of the player, but motion controls seemingly track like normal.
Expected: Motion Controller meshes are tracking with hands.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-69820 in the post.