The only reason it is taking this long is because you are HRing all the wealth the dragon drops. If you don’t HR and you win it fair and square, I promise you that (even though it can still happen) it’s going to occur way less likely and your group will fill faster. A lot of players don’t like when people HR and even when they join groups, do so grumpily because there is no other groups available (and they don’t want to make their own).
I’m just letting you know this type of retaliation is going to be common when you try to steal all the riches for yourself.