Are you booking your trips less than a week in advance? I was asked more than a few times by CBP agents why I was traveling so much last-minute. I answered honestly and said 1) my boss is a last-minute seat of the pants guy and so I do a lot of biz trips last minute and 2) I look for last minute holiday deals since I'm always packed anyways.

I also mostly travel carry-on only that seems to raise flags. I am almost always questioned twice by CBP bc of my travel habits.