Like the others said, the AUTO only engages the 4wd once you’ve started slipping and then goes back into 2wd once you have traction again. This is great for on-road slippery conditions where you can’t use 4wd most of the time. But in deep snow or mud or other consistently slippery conditions, you want it to stay in 4wd so it doesn’t slip in the first place so that’s when to use the manual 4wd settings.