After conducting the test 10 times, all resulted in failure
An error occurred when running Lighthouse: FAILED_DOCUMENT_REQUEST. It seems that Lighthouse was not able to load the requested page reliably. Ensure that you are testing the correct URL and that the server is properly responding to requests. (Details: net::ERR_CONNECTION_FAILED)
This could indicate various issues such as your page failing to render in Google's PageSpeed Insights, a disruption in the internet backbone, or another issue altogether.
It is possible that an internet backbone outage disrupted the connection between your server and Google. When such outages occur, some users may be able to connect while others cannot. Check your logs for IP addresses associated with Google's IPs when accessing Google PageSpeed Insights.
To eliminate page rendering as the problem, try moving your index.html file elsewhere and replacing it with a dummy index.html to see if page rendering is causing the issue.
To rule out an internet backbone outage, switch to a temporary server and move your content there. If Google PageSpeed Insights function properly on this new server, then the outage was likely the cause.
I hope this information proves useful.