Are you running multiple wallets from the same computer? My understanding is Evan changed how DS works, like if A pairs with B at the first round, A can't pair with B again until much later or not at all. So on Testnet it takes 2 participants at each round but not the same 2 participants on every round. Also, your pairing has to be at a different masternode each time, or not too recent, this is why DS can take a long time. (And I hope DS works like this or even more complex, because if pairing is so easy and frequent with same participants. it's not going to accomplish anonymity and the code needs to be revised, imho.) I can be wrong and hope someone else who knows better can help us to understand better.