StaffLabelsFull - German instrument names

I have a problem with the token {@StaffLabelsFull@} and German instrument names and transposition:
I added a “Trompete in Es” and it looks fine in the Score. If I change the token {@LayoutName@} to {@StaffLabelsFull@} in the part layout, Dorico adds a flat symbol behind the “Es” and I can’t find a way to get rid of it.
Same is true for Trompete in B, where Dorico is adding flat symbol, even if I told Dorico not to do so.

I am looking for an automatic way. Otherwise I just could have edited the layout name.