I bought a Adios Star Stellina last month. And I love it so much. But I noticed that after a few uses the zipper started to jam/get stuck. Its only when I zip it up completely to the end. And it doesn't look like its lose any teeth. I'm wondering if others have had this problem and know of a way to fix it? I try to be more cautious and not zip it up completely so it won't stuck but when it does happen I struggle with it to get it open. Thank you!