Boss Kill Not Counted in The Silent Cave (Possible Bug)

I encountered an issue where after killing the boss in the unique map The Silent Cave, the kill didn't count. I checked the entire map—there were no remaining minions or monsters that could be linked to the boss and count as part of the encounter. I also tried going to my hideout (and because the boss kill wasn’t registered, I couldn’t open the portal in the center of the map), relogging, etc., but nothing helped. This seems like a problem worth addressing. Thanks!

I ran into this issue again. I got the map once more, but this time I tried a different approach: I killed all the imprisoned monsters around the arena first. Still didn’t help. Now I’m certain this is a bug because it’s happening consistently. Thanks