I have a 2014 Suburban LTZ with the Z55 suspension. Up until this past weekend the auto leveling has worked fine, for both heavy loads in the back as well as towing a popup camper. We recently upgraded to a travel trailer (6000lb, 700lb tongue) and our first trip was this past weekend. When I first hooked up the truck it leveled fine but while on the highway I started hearing the tires rubbing on turns. I pulled over and the back end had dropped significantly. On restart it brought it back up to level without issue. I had to do this twice during the trip (1.5hrs trip). I was towing with a full freshwater tank as I wasn't sure about access to water where we were going so I thought I may have just been to heavy on the tongue weight? On the return trip I made sure all tanks were empty and all gear was in the back to reduce the tongue weight. Again it initially levelled fine, and this time took almost the whole trip before I started rubbing again so it's definitely related to tongue weight. The questions are, shouldn't it be monitoring during driving to keep it level? Or just when you first start the truck? Based on the GM towing guide for that year it should be able to take up to 1000lb tongue weight (if I read it correctly)? So not sure if my issue is a leak in the leveling system, too much tongue weight, or a system problem where it only adjusts on startup? Or some combination of all three? Anyone else experience this issue?