This time of year and 24% moisture, my guess is that you probably have some "green" material hanging up on the concaves. This can create a large rotor loss like you described. Open the side up and look to see if this is the problem. I am not a huge fan of pulling wires, but in this situation it can be a great help. Try pulling every other wire in the first half of the concaves and see if this helps, if this is the problem.