@ttv002
I have attempted to reproduce the issue you are experiencing, but have been unable to do so.
The application was tested on a PICO 4 headset running firmware version 5.13.7.S across multiple internet connections, and no issues were observed in any of the test scenarios.
As you mentioned that you have already performed a factory reset, ensured all system updates are applied, and contacted your internet service provider, the next best step would be to review runtime logs from the affected device to better understand the root cause.
Could you please connect your PICO 4 headset to your fibre network in developer mode, launch SideQuest, and use the Logcat tool to capture the application run logs?
In SideQuest, click Start to capture, then put on your PICO 4 headset and launch the DeoVR app. Allow the app to run until it reaches the spinning loading screen, wait a few seconds, and then return to SideQuest and click Stop Capture.
Once captured, please share the logs with us for further analysis.
For reference, the image below illustrates how to capture run logs using SideQuest’s Logcat tool.

You can download the SideQuest app from https://sidequestvr.com/
Don't forget to connect the USB cable from your PICO 4 to your PC when capturing 🙂