I'm not sure when, within the past few days, all of my challenges reset. I'm not going to complain since the first time you complete some you get a much better reward and I get to do that again, but figured I would report it anyway. By reset I mean that I logged in today and it said I hadn't completed any and only the first row is available to me. When I complete them others are seeing the completion (so the server really thinks it is the first time I am completing them). I had been up to the level with the 500 gold blocks (page 2). My island level has remained the same. My balance is correct. My island hasn't changed.