This may be a bit crazy...but....did you have an old machine that you had to "help" by guiding the fabric thru with your hands in front of the stitching and in back??? In other words, gently pulling?
I have a bit of experience with that. When we get a new modern electronic machine, we don't break our old habits and the new machine doesn't like it.
If this isn't the case....great...
If this helps...GREAT!