Did you attack the boss? One of the weird things about how it works is that despite being in a party, you need to individually whack the boss with something to get any credit at all. One Stone should have done it (although several is safer), after which your healing counts. Why? Reasons. But it's not like a dungeon where if you wind up spam healing and never hitting what the party is fighting, you still get full credit. In Eureka, you MUST hit it at least once.
One time I was running to a NM that the tank in our party was already at. It was at 10% by time I got there. Hit it with a single Fleche. Got gold, because our tank was there for longer. It's unfortunate you didn't get it, because Rider would have been worth several thousand XP to you.
That's what I was thinking too. If you like the Omega story or not is subjective, but it does make an attempt at having one (shamelessly fanservice-y though it is, Omega was first mentioned back in ARR, so its not like they just pulled it out of nowhere). Kugane Castle has more story than Eureka does right now, given that Eureka's story is all in the setup. Once you get in there, basically nothing happens. Krile complains that the aethernet is still blocked by stuff even after you've regained access to it (not that the game tells you when you gain access to it)... and thats it. The shielded buildings you can see on top of a cliff give more story than the actual story, and they don't do anything except sit there.
For a game with three seperate stories about being a weaver, to have such major new content not even bother to try is baffling. Maybe there's something at 20, I dunno.