Online dropping only on

I had a few hours of downtime in January but every other node has been going up since the outage, while keeps dropping. Any clues?

Please, check your firewall, perhaps it’s blocking traffic from the satellite. The online score is dropping when the satellite cannot get an answer on audit request from your node.
It will recover as soon as your node would start to answer on audit requests, but will take 30 days online to recover.