Right! If the base moves, you will never reach the tension you're looking for. Holding it by hand will have no success. Check this video: At around 36:50 he says how the clamps bases can be fixed/tighened. I think in the past there was another thread in this forum about tightening clamp bases (the ones you're using). Unfortunately I couldn't find it, sorry. Another thing you should look for is to clean the rails and the clamp bases with e.g. isopropanol. Depending on how much rackets you string, cleaning it every month. Hope this helps
Stringster app has given me a similar problem strung Duora Z strike at 27lbs and straight after stringing said strings were fresh at 22lbs but checked my machine and tension so think the app is just not registering properly my strings feel a lot tighter than 22lbs
