I have a brand new klippermate and have strung my racket, a prince pog mid, three times. I have cleaned the string gripper very well but my strings continue to slip a little. The first time it started slipping I was using alpha gut 2000 and I figured it was the strings. I just strung my racket with mantis comfort and I cleaned the gripper thoroughly before I started. But it still started slipping. Assuming it's the strings and not the gripper what can I do to keep the strings from slipping. I'm using head rip in the mains could that be causing the slippage for the crosses? Or is it the gripper?