Me and my friends operate multiple relays and exists, but suddenly they are all offline(by metrics.torproject.org). They are all on Ubuntu/Debian servers, , they are in different locations, datacenters and we bought them from different providers. We are using official tor deb repo.
I have no idea why did it happen. Does anyone else had the same problem before?
Most likely, it happened because of incorrect MyFamily settings.
To check if it is the case, you can look into logs and search for rejected fingerprint errors.
Also check your contact e-mail, explanation may be there too.