I examined it for some days now and have a feeling that the more I pay attention to pressing the buttons in an exact 90 degrees angle the more reliable they react. When I press them in a more sloppy way while working fast and jumping around on the screen building something up, maybe pressing them more on the edge than exactly centred they make the same clicking sound but the software does less likely react. I guess that’s just how those knobs are.
It mostly came to my attention with the “up” button because when you focus/defocus a control and the defocus process does not work you then change the value again with the encoder instead of moving to another control on the screen which is a bit cumbersome sometimes. I think I wish the focus/defocus routine would not require the “up” button for being able to switch through the controls a bit faster when setting something up. Maybe the focus-press to switch through the control mode screens could be replaced by pressing enter on a focussed control?