[screwdriver]

all my aegs apart from my marui m4 do this, to alleviate the problem i just lightly tap the trigger in semi to pull the piston back in stages and then the final tap releases the piston ready for storage.
this is why ive never understood why all aegs dont have the spring release lever like the ics m4 and g&g sa80 has.
though as mentioned before some guns ive upgraded for others were prone to doing this but stopped after the springs were greatly upgraded.
an extra note is that if your semi cut off lever wears greatly youll loose semi completely and have full auto only, the torque in the gear set with a lower power spring will continue rotation even after the cut off lever cuts power to the motor