The bisquettes feed freely without any additional weight. The Bubba Puck - aka bisquette savers; do two things. If you use two, they advance the last two bisquettes on the tray to the burner. If you use three, they advance the last two bisquettes, and then push the last bisquette off the burner. Bradley claims that burning the bisquettes longer than 20 minutes will produce a bitter smoker.
If your bisquettes have been exposed to too much humidity, they can swell and that may cause a problem in feeding. Try using some other bisquettes from a different box; newly opened if you have any that are still sealed.
From what you describe it could be that your tube (chute) may be improperly installed. Make sure that the tube is straight. Also where the tube is inserted into the generator, there should be very thin lip. The end of the tube should be resting on that lip and it should not be inserted past that lip.
Other things to check, is to make sure there are not dents in the tube, and that the inside of the tube is free of debris and/or manufacturer's defects.