I know, for me, it was my mat and not the blade. If you are like me, I often line up fabric on the same line and that area or measurement line wears out faster or develops little nicks in certain spots causing the blade to not cut through at that spot. To fix this, I flip the mat around and try cutting on varying measurement lines to extend the life of mat. Another time, it was the cutter and not the blade. Maybe you could try that blade in another cutter to rule out cutter issue. Yes, it is indeed frustrating.