You may have to seperate issues. First you probably need to rotate your arrow nocks to eliminate the contact. You did say you have a shoot through rests. 2nd a 29" 2216 shot from a 68# bow may be a bit on the weak side as far as arrow spine. This is assuming that your shooting a fairly modern or recent manufacture bow with a single or hard cams. That also may be an issue. I suggest paper tuning and rotating your nocks to see where the problem is.