I’m trying to find an answer for my Dad, but I also sew. He says his 30? year old Kenmore is having a problem where it sees correct stitches, but when he goes to pull the fabric out to skip the threads, it snaps the top thread. He knows how to correctly set up top or bottom tension, so that’s not it (and that’s all I can find on the internet). Any ideas? I had him clean the tension discs, but it didn’t help. He’s afraid of taking things too much apart and doesn’t have much extra money to just take it to a shop. Thanks!