We recently replaced the blade in my MH721-MK2 cutter. The blade cuts fine for about the first 5" across and then has about 5" where it doesn't cut deep enough and is impossible to weed. It's almost like it is just perforated. If I cut down instead of across the vinyl, it weeds fine as as long as the design doesn't go past 5" . I am using heat press vinyl and it's a roll I've used before. Any idea what could be wrong? I would sincerely appreciate any thoughts or comments on this issue. Thanks!