Hi… I don’t speak for Fly.io at all, but generally for things like that you need one of the Support plans. Occasionally a Fly employee will drift through the community forum here and look into something out of personal generosity (or just curiousity, 
), but that really isn’t the default…
It sounds like you have a fairly involved operation there, so having that would be wise, anyway. Going without support is really only for hobbiest dabblers like myself.
The Fly.io platform is prone to losing single Machines. Generally, you should have ≥2 per app. The most common cause is a failure of one of the underlying physical hosts.
If you can still see the Machine in fly m list, you can try fly m status to get the events list. That’s a little cryptic sometimes, but it might give some hints. (E.g., an attempted migration.)
The app-level logs (fly logs -a app-name) should also be consulted in such situations, as a reflex.
Hope this helps a lilttle!