Its part of the experience as a bounty hunter. In my case, I have not been paid in half of the bounties I joined especially when I was new and joined any campaigns I find. But now im more particular in joining bounties and look deeply to the project and the team running it.
Well the thing is, you can expect the unexpected things to happened. Therefore as yu continue supporting the campaigns you will soon enough get the profit. It is like doing things that you would not expect to happen. In campaign you need to be smart enough in choosing where to join. It is about how you play to win.