Peer, if you always want to use a single voice for your drum parts, you can also select each instrument in turn in the Edit Percussion Kit dialog and make sure that they are all set to up-stem 1. Then you’ll always get a single voice for your drum part, regardless of the state of the option in Notation Options.
Thanx Daniel for the great support. I don’t know how I could have figured that out by myself.
I’ll be working with your advice now. If I get stucked, I’ll come back. I’m curious. Up till now it worked. Fingers crossed 