Are you pointing too high with the spinnaker, making it too hard to hold?

Are the spinnaker blocks ratcheting? Did you put the sheet in the correct direction?

If you think it is the spinnaker sheet which has become hard to hold/handle, can you "end for end" switch and then be holding a different section of the line (or is it tapered?) to determine if it is just that part of sheet that is slippery?