I would suggest you spray the tailend of your arrow with some foot powder spray and see where it rubs off after a shot!
If you are getting a rub mark under the arrow shelf you are getting arrow contact.
If you are shooting with ****vane down,try shooting with it up,I have an old style rip-cord and after getting it adjusted properly I can shoot with the ****vane up/down/in/out and don't see any differance in arrow flight.
With a few adjustments you will be more than pleased with the rip-cord, I love mine. Good luck