Desktop Editor does not transition into VR Mode when Oculus HMD is worn while 'Enable VR Mode Auto-Entry'=True

Desktop Editor does not transition into VR Mode when the Oculus HMD is worn. The user must manually enter VR Mode using Toolbar buttons / keyboard shortcuts.
This issue is only observed when on Oculus; Vive transitions into VR Mode when the HMD is worn.

Regression:
Working: //UE4/Main, CL 3512782
Broken: //UE4/Main, CL 3512933

1. Select Edit > Editor Preferences > VR Mode
2. Enable 'Enable VR Mode Auto-Entry'
3. Put on the Oculus HMD

Result:
Desktop Editor does not transition into VR Mode

Expected Result:
Desktop Editor transitions into VR Mode when HMD is worn and Enable VR Mode Auto-Entry = True