When selecting the Onyx Hive to play, the description includes this information about their ships not repairing.

That can be assumed to mean the ships heal some other way, not that they don't heal at all. Perhaps delete normally. Derek reported on Discord that they don't heal at all.
Since their ships don't heal, there are some errors in their ships.
They can build a Caretaker ship, which heals ships, except that is doesn't.
Their Command ship "Victory" gives +2 Fleet Repair per Turn, but it doesn't. Also, Turn should be Week. Using Week instead of Turn may apply to Command ships of other races.
Their command ship "Hivebase One" gives "Allied ships within the Area of Effect Repair 4 Hit Points per turn." Also, turn should be week. I don't have any allies to check this, but my ships don't repair. Does it mean allies or Onyx Hive ships?