Judging from the folds, I'd say your waist is too tight. Seems the whole back part of the dress is resting on the small of your back. AND you have "pulling folds" from the sides to the zipper at your back. If you can, let some fabric out of the seam allowances. Maybe the dress will then fall a bit down and smoothen your problems.
Timing wrong? The needle has to be at an exact point at a certain stage. Not that I know which one that could be. Nor if you can handle that yourself. But if you say it's jamming the bobbin... well, I'd consult a technician.