I have a 35mm Leupold/Gilmore red dot on my turkey gun. I decided to switch the battery as a precaution. I tried to turn it on at the no. 1 setting and it will not light. It will light on no. 1 if I stop just short of the switch stop for that setting. All other settings 2-11 are working fine. Does anyone have a clue as to why this may be happening?

Thanks