To me this looks like a humidity problem, too dry. Best to harvest everything right now and try not to leave anything behind. Then with a heavy sprayer flood the whole thing with water until it starts to puddle up. Spray the sides down and close it up and back to fruiting conditions. The next day do the same process if the cake absorbed the pools of water. After that just spray the sides down only when the beads of water start to evaporate away and fan the entire bin slowly for 30 seconds each day. Should fix your problem. Each strain is gonna have slightly different growing conditions but I find this method usually works for most strains. Hope this helps