I'm having a major roll axis drift issue. I have a 1DX II mounted with a 16-35 mark III lens. Balanced almost perfectly. However, the horizon drifts almost to 9 degrees. Sometimes it'll drive to 1 degree, then minutes later it'll increase to 5 degrees. Someones it'll drift to the right. Sometimes to the left (without re-balancing). I've restarted multiple times during shoots. It's killing me. Almost ruins shots and I can't get things working right. Please help??