Welcome from Ontario, Canada. First clean your bobbin case area out and under the feed dogs. A fluffy or piece of thread can mess things up. Try a different bobbin to see if that helps. Try a different thread in the bobbin, some are smoother than others.
Lastly, try changing the tension on your bobbin case. Note the position of the slit of the tiny screw before moving it so you can return it to the original position if that is not the problem. Use the tiny screwdriver that came with your machine. The screw goes tighty righty or lefty loosey. It sounds like the thread tension may be a little tight?