Whitetails will often follow each other with scent and movement. They will see a deer ahead; and go to where they can smell them. They do this all year.
I am wondering if; although your wind is good from where you are sitting- what is it doing where the deer is?
Wind changes directions; gets pushed right and left when it hits trees; and brush; and what might appear to be a perfect wind; where the deer is; might be perfect for him.
I like to check the weeds and grasses where I have a stand; and see what direction they are falling over in. That seems to be the prevailing wind. You might walk from your blind to where the deer smelled you; and see if the wind is moving your scent to it; and adjust your stand position; or lay brush on the trail; forcing the deer to go where they cannot smell you.
Movement indeed is the thing that moves them out fast; after they get a whiff of you. Move slow and deliberate- and whenever the deers vision is blocked.
face paint; or a head cover can work wonders.
The best blinds though do not allow the deer to see you until they are in a position where you can shoot them. Deer are more likely to see something on a trail (or in line with their direction of travel - than next to it- off to the side.
Deer commonly wind their way instead of going straight in a direction- to help smell us.