No unpitched percussion

Every now and then when I want to change instrument in setup, there is no unpitched percussion available.
If I create a new player it appears among the choices available. How come?

If you are trying to change from a pitched instrument to an unpitched one, there might be technical difficulties converting pitched music to unpitched music?
Unless you are trying to change from one unpitched instrument to another.

Yes, you cannot change from a pitched instrument to an unpitched one, or vice versa. Add a new instrument and then copy and paste the music manually if that’s what you’re trying to do.

I understand. Thank you. This actually was an imported percussion instrument with two lines via XML but it is probably not interpreted as percussion in Dorico.