I have a 2015 John Deere 3039R and the H165 loader. I noticed the other day when lifting loads of gravel for a project that the loader masts are lifting off the mounting frames on both sides with a full load. I was able to put the bucket in 20 degree position (attachment procedure) and heard the masts pop back onto the mounting frames and end plates. I am still seeing a bit of lift on heavy loads that I am not comfortable with. Seems to be one side more than the other. Nothing unusual about the weight, lifted this 1 1/4" processed gravel material at this weight many times before. I have proper ballast and loaded rear tires. The machine is fairly new to me so I have not taken the FEL on/off before. Manual only seems to talk about checking torque on the frame and loader bolts. Is there some adjustment that I should be looking into on this?