KAHLER issue

[Valvehead]

I just installed a flat mount Kahler. its all set up and adjusted proper according to the Kahler videos . Also have the new nut which is the flip lever style . New strings --properly stretched. This thing wont stay in tune !!! The locking nut is nice and tight...the bridge operates smoothly . But repeated use it will go a little flat or sharp depending on up or down with the trem bar.

Any ideas ?? The only thing i can think of is maybe the cam block underneath is barely rubbing on the wood?? Maybe my route needs to be a few mm deeper ? But i cant feel any dragging