I just got back from the range and I got a couple of rounds in before it started raining. I had no problems prior to the rain. I shot my arrows a round or two in a light rain and then the next round the arrow would fall off of the string after I got it pulled back. I tried about 10 times and with different arrows and everyone fell off. The arrows ar carbon express. Should I get different knocks, I tried to bite the knock to make it pinch harder but that didn't work either. What should I do?