Interpreting belt tension graphs

I just upgraded my Vcore 3 to 3.1 and Ratos 2.1 RC3 tensioned the belts to a kina equal tension just by sound and now ran the frequency measure belt tension macro The first Result I interpreted as lower belt being too loose, increased by half a turn and ran the second test. It barely changed and from the tone the belt makes when manually "stroking" it the lower already sounds higher (so more tension) Did I get something wrong here?