Last week when the temps were above 100 degrees my 39-0-0 XCU started to melt in my PG. When I arrived at my next lawn the top 1" of the fert in the hopper was hard. I would have to remove it and crumble it up with my gloved hands. I even left the cover off several times to keep the humidity and heat lower. By the end of the day the bottom of the hopper looked like ice sickles. It looked like I had washed off the PG with a water hose in sub-zero temps. I have never had a problem with any granular fert. I was not using the sprayer because my lawns are clean. Just throwing fert. Anyone else having problems with XCU either?