Just got this sight and was messing around with it and found the dot disappears in the top half of the viewing area. It goes all the way to either side but not up to the top. I messed around with the elevation adjustment and with it turned all the way up the dot will go a bit higher but still only reaches about 3/4 of the way. I've never had a red dot sight before but I can't think of anything I'm doing wrong. Is this thing defective?




















































