does it leak till empty or does it stop?
what are you filling with?
could be a bit of debris in the foster fitting.
or,
since its a new gun,
try shooting some of the pressure down and fill it again,
sometimes the check valve in a new foster fitting needs a few cycles to seal properly.
or,
if you have a hobby shop that sells rc cars/trucks near you,
you could get some 100% silicone shock absorber oil and put a tiny drop into the fill nipple and then fill the gun a bit to distribute the silicone.
i have the virtus and LOVE it,
dumping a full mag is.......magical
dont forget to use the pellet seating tool housed in the grip to seat the pellets.