Can't I make parametic sweep at PSPICE?

I want to sweep gate's offset voltage of the CS Amplifier.
I set VOFF as {VOFF} and added device PARAMETERS and made parametic sweep.
And you can see it works well (VOFF=1 to 10)
BUt the result is 0V/V at output what happens here?

Can't I make VOFF to variable?

P.S when I make Resistance or capacitance to variable, it works.