Okay, I wrote a script where I did re-send the value of a knob, as soon as it is clicked (via Knob1.setValue(value); and Knob1.changed();). But that doesn't solve the problem.

Also I recognized that with any other plugin the corresponding automation track in Nuendo is highlighted "red" as soon as I click on any parameter (when the track is in "write" mode).

But with my HISE plugin, it doesn't. It also doesn't turn "red", when changing a parameter.
So there has to be some kind of message that the plugin should send to the DAW but isn't. Does anyone know something about that and maybe a way to fix that?