My Janome dealer (who is a very smart guy) said that all cotton thread is not the best to use, that you should use wrapped cotton or polyester thread. He also said that it is AN OLD WIVES TALE that polyester thread would cut cotton cloth, that it is not true. So try the poly thread and see if that works. And change needles often. Sometimes they have a burr, and every other one in the package will have the same burr.
Had the same problem with a different needle and cotton wrapped poly. And the 'new' Mettler cotton and quilting needle worked on one fabric and not on the next. 50 years sewing on any cheap machine I never saw this before. FINALLY got a 'good' machine and it is too finicky for me.