I have a 2018 Suburban LT. when it’s very cold (below zero) I need to use the “manual” setting because the power one is inoperable below 4 degrees. When I turn the button on the ceiling to “manual” and then manually try to open the lift gate, it unlocks but when I go to lift the door manually, there is so much resistance that I can’t raise the door at all. The power opener works perfectly if above the cut off temp of 4 degrees. Anyone know what would make the manual option inoperable?