Today I went to the wasp cave in Gold Creek to defeat some drones (quest 'It's A Hive!' for Postman Abe. I went to the Queen's area because people were fighting here and there were a lot of drones. However, It said combat full, but it joined me. I thought that was weird and it turned out that there were Five people in the battle, including me. That is the first time that it has happened for me. Then we finished the battle and collected the chest. The second we got the last chest, it made all five of us started the battle all at once. Hope this helps. Witty Gavin Bristol-level 26 swashbuckler I had my Weasel Gambler, level 28, Toreador Novillero, level 24, Sarah Steele, level 23 upgraded once, and my Orchid Chameleon. (I think I was supposed to list my companions in the battle?)
I was in that cave in the last week too and once we finished the fight it took us right back in after the last chest was opened too. Once we finished the second fight though all was as normal. Not sure what is going on there.