Are you using the plotter's Auto Pre Feed function? If not, try enabling it. If so, what speed is it, normal or slow? Try slow.
The actual length of the pre feed doesn't matter but the shorter it is, the more often the plotter will pause to pre feed, the longer it is the more loose media the machine has to wrengle. The default is 3 feet, which is approximately the distance from the feed rollers to just slightly above the floor. This a a pretty good choice if you don't have an actual reason for setting it to something else.
If you have the auto pre feed set up properly for your situation you'll seldom, if ever, pull the vinyl off the feed rollers. If you don't use it then you'll constantly be jerking the media off of the feed rollers. Especially when the media off the roll has more intertia than the media left on the roll. Not mystery, just physics.