Volume knob for sampler on mixon 4 don’t work

I have a mixon 4 and am quite satisfied with the new app on my iPad pro but can’t get the volume knob for sampler to work, it is midi-mapped correctly but nothing happens when i turn it, it works in the old app.
It would also be dope if you could control the loops volume with the same knob or map it to some other knob. I also miss the funktion to add my own samples.

Thank you Pat