There is a ZPL command that calibrate's the media sensor that might be useful here. The command is described on page 223 of the documentation you provided. Note that this command does not require any parameters so you should be able to simply use ~JC to calibrate.
Thanks for your response, your suggestion did what you said but did not fix the problem. I was able to fix it by tweaking the printer width and print mode (MM) to peel off instead of tear off. This is what it looks like now:
^FX Example of comment
^FDBest By Date^FS)^FS^FO0,50
^FDTop Sirloin Steak^FS)