[MelBonis]

Bounce: the last year  I had always 0,5 seconds. With problems in the concert I changed to 0,0. nothing better or different. Today at home both works perfectly.

As it had happened already once, a year ago, also on this specific stage, but with different tablet and different bluetooth pedal:

I had thought,
-maybe I did too much turning with fingers, and also foot, and too often backwards to the beginning with three fingers, through all pieces. This happens only before this sort of concerts on this stage. Because I extensively practised page turn passages in the end.
-also the turning seemed to be much slower and in different tempo each time, other than normally. Anyway I closed everything, and rebooted. I had a little problem with pairing then, bluetooth only worked when I held the tablet nearer to the pedal. Nothing had changed afterwards. Not quicker, pages jumped now and then.
-maybe only this stage, a problem of  bluetooth, disturbed by some power circuit line under this special stage.
maybe this  one grand piano is the problem. It has a built-in air-condition. (I put it off both times after problems, first time , in the concert last year, everything went well ... by chance?)

I tried to reproduce the problem today, turning back and forward a lot. But everything is perfect, page turning is super quick and confident.