Exception in XR Hand tracking when leaving immersive mode & returning

[Palmer-JC]

From Forum topic

When using handtracking, then leaving immersive mode. When you come back you get a black display. Console throws following exception:

Uncaught DOMException: Failed to execute 'getJointPose' on 'XRFrame': XRSpace and XRFrame sessions do not match.
    at https://192.168.50.238/babylon.js:16:3396139
    at Array.forEach (<anonymous>)
    at e.updateFromXRFrame (https://192.168.50.238/babylon.js:16:3396083)
    at https://192.168.50.238/babylon.js:16:3403108
    at Array.forEach (<anonymous>)
    at HandTracking.t._onXRFrame (https://192.168.50.238/babylon.js:16:3403058)
    at HandTracking._onXRFrame (https://192.168.50.238/Palmer-JC.github.io/lib/XR-UIPortal.2.0.js:1809:19)
    at r.callback (https://192.168.50.238/babylon.js:16:2097536)
    at e.notifyObservers (https://192.168.50.238/babylon.js:16:37003)
    at XRSession.renderFunction (https://192.168.50.238/babylon.js:16:1341566) 

Running Babylon.js v5.0.0-alpha.8 from a local webserver by IP address.