I would make sure your rollers and sprockets are clean. Also make sure that your wipers don't have any glue on them, that can catch and snag at the vinyl and slow it down. Are you using Gerber Foils or a mixture of foil brands? Try using all of one type or sub out the cyan for another foil to see if it's a problem with the foil. Is the cyan wound tightly? That is my ADHD brain dump for the evening, hopefully that starts to narrow down the problem.