You are probably getting hung up on the bottom of the hole, what happens is it doesn’t make a complete hole if you bust through too fast. What I do is once you get close to the bottom kind of ease up on the throttle and let the auger cut a little slower so it opens the hole completely.
It’s kind of a feel thing and takes just a little bit to get used to. Don’t push down on the auger when it close to busting through, your probably used to doing that with your old auger, let it do the work when you close to the bottom.