Perhaps your stand placement is so close that you're also getting busted by sound. I've groundhunted and had deer come within 15ft of me and not have a clue until I tried to draw down on him. At that close the deer can actually hear you breathing if you're not careful. Maybe place your stand farther out from where you intend to shoot. It's extremely difficult to draw down on a deer under 10 yards without getting busted.
Also, maybe you're stand placement isn't high enough to be above the deers natural vision plane. Try getting higher?
Good luck, hope you tag your limit this season