These are the steps I have in my guide, all works ok here.

Meta XR Simulator

1. Unzip "meta_xr_simulator_v72.zip" file to "C:\Users\name\Documents\Unreal Projects"
2. Uncompress the .tgz file within the "meta_xr_simulator_v72" folder
3. Set the "Meta XR Simulator JSON file" location in the Meta XR plugin: C:/Users/name/Documents/Unreal Projects/meta_xr_simulator_v72/com.meta.xr.simulator/package/MetaXRSimulator/meta_openxr_simulator.json
4. Close the Project Settings window
6. File/Save All
5. On the VRTemplateMap Tab locate the "Meta XR Simulator" menu
6. Open it

https://dev.epicgames.com/community/learning/tutorials/PYP7/unreal-engine-5-5-x-for-meta-quest-vr

You're correct, I have just redone everything, and the rooms are no longer showing under "Meta XR Simulator/Synthetic Environment Server". I also noticed a "Meta XR Synthetic Environments" path in the Meta XR Plugin, but I'm not sure where it should point to (I tried lots of random locations).

It looks like the rooms are missing from v72 (as you noted), and v71 doesn't seem too thrilled about UE5.5.0. Perhaps Meta needs to work some magic, or we could be missing something.

When setting the path to the MetaXRSimulator folder, I no longer see room listings as I did before. Maybe this has changed? I rarely use the simulator, so I may not be the best reference.

SOLUTION: I went back to previous XRSim versions until I found one that had the folders with the synth environment server and the ses_rooms.
I copied them to the new versions and ensured the names are correct (Looks like they changed something with ~ in some version?)
I pointed the rooms config to the XRSim folder.

Seems like someone messed up at some point in the XR Sim release and isn't including necessary files anymore.

Meta XR Simulator Setup Tutorial

Below is a tutorial organized based on the provided file content for setting up the Meta XR Simulator, based on GiovanniCocchiara's testing.

1. Download and Extract

1. Download Files:
   • Go to the official website and download v71 and v74 versions of Meta XR Simulator.
2. Extract Files:
   • Extract both versions to your local system.

2. File Copy Operation

1. Open the meta_xr_simulator_v71 folder and navigate to the path:
   meta_xr_simulator_v71\package\MetaXRSimulator.

2. Copy the MetaXRSimulator folder to the following path:
   meta_xr_simulator_v74\package.

3. If prompted about duplicate files, choose Skip Duplicate Files.

3. Configure UE-Oculus 5.5

1. Open UE-Oculus (version 5.5).
2. Go to the project settings:
   • Project Settings > Plugins > MetaXR.

4. Configure Meta XR Simulator

It is mandatory to use meta_xr_simulator_v74 for configuration.

In the MetaXR plugin settings, complete the following configurations:

1. Meta XR Simulator JSON File:

   • Set the path to:
     .../MetaXRSimulator/meta_xr_simulator_v74/package/MetaXRSimulator/meta_openxr_simulator.json

2. Meta XR Synthetic Environments:

   • Set the path to:
     .../MetaXRSimulator/meta_xr_simulator_v74/package/MetaXRSimulator

5. Setup Complete

After completing the above steps, the Meta XR Simulator is now properly configured and ready for use.

The setup was successfully tested in the latest UE Oculus 5.5.1 Phanto test project with image rendering as a reference.

Unfortunately, the engine's built-in MetaXR project has not been successfully configured yet. This might be due to some other settings issues or official compatibility limitations.