Synopsis

After you edit one of the sample simulation environments, upon leaving prefab editing mode the Sim Env seems to revert to its unedited state in AR Environment view.  In actuality your edits have taken effect; to see this enter XR Simulation mode, or Re-import All in Project view. 

How to see the Bug

In an AR Foundation project, install the sample simulation environments. 

In AR Environment view chose a Sim Env other than DefaultSimulationEnvironment.

 AR Environment > overlay menu > Edit environment. 

You are now in prefab editing mode.  Move one of the objects in the Sim Env. 

Exit prefab editing mode by clicking the "back arrow" near the top of Hierarchy view. 

AR Environment view shows the Sim Env prior to your edits. This is the bug. 

To recover, click the Play button to enter XR Simulation mode, then click Play again to exit this mode. 

Another way to recover: right-click anything in Project view and choose Reimport All. 

Configurations

This happens on both Intel Mac and M1 Mac – not sure about Windows. 

Bug occurs with both Unity 2022.2.0b1 and 2021.3.6f1.

Occurs with 5.0.0-pre.12 and pre.13.