I had a strange (sync?) error this evening too. I was trying for black swan. I would have bred night/night, but my 2nd night was exhausted from battle. Instead, I bred 8/Kitsune x 4/night & got 12 hours. I was ok with this cause maybe I would get the phoenix or celestial... Some time later (not sure how long, maybe an hour or two) I saw my den was empty. Very strange. There was nothing breeding.
Since I didn't get a that 17 hour timer I was hoping for, I decided to go w a different combo. I put on 7/rainbow x 10/air & got a 21 hour timer!! Hopefully it's the starry night! I'm going to try & wait for tomorrow to speed.