First make sure you do not have halyard wrap above the upper swivel. Can you furl and unfurl the sail easily, indicating no problems with the drum or upper swivel? If all is well, try hoisting the headsail halyard a bit higher. Then release it and pull the luff of the sail down firmly. Sometimes, the luff tape will stick a bit due to being the same position for a long time and it accumulates grit and dirt between it and the extrusion. If all is well with your halyard, swivel and drum, give the luff a good yank after releasing the halyard. Good luck with this.