I was able to solve the problem. I added a "holdState" flag to the touch button query. If I press and hold a touch button, other buttons are locked. If I release the touch button, the other touch buttons are unlocked (see my Video).
// read...
Ok. I still have a small problem. If I move my finger over the slider area and come close to other touch zones, e.g. "Program" or "<Page", then the function is aborted and another touch function is executed (see Video).
My code..
// Loop...