Hi,

It works fine here but I'm don't know your setup:

I can try your scene if you attach it here. 

I don't know what you are trying to accomplish but have in mind that any manuall UV editing will be destroyed if you change the hair down the stack. Any changes made in any node down the stack will recompute the whole hair stack, including the UVs. 

Jeordanis Figuereo (Product Designer. EPHERE Inc.)