I have a Mouth Organ in Eb Major and named it "Mouth Organ (E{@flat@}) in the instrument names window.
The flat sign is shown correctly in the part (with the {@instrumentlist@} token - however in the score the hex code is shown rather than the flat sign (see screenshots).
Also something weird happens with the Touch Bells: their name is displayed correctly in the score, but in the part the {@instrumentlist@} token interprets the “Be” in the name as a flat - so it is shown as Touch{@flat@}lls
It seems that the instrument’s staff label doesn’t interpret the token, indeed.
There could be better solutions but meanwhile, what you can do is:
Instead of using the token when you edit the Intrument name, use a software like Word (or any place in Dorico which supports Unicode) and type the corresponding code (I used Alt+9837 on Windows; otherwise, the Unicode is apparently U+266D)
Copy the symbol and paste it into the Editor:
That way, the display looks correct in the staff label and the Instruments List.
(As for Touch Bells, I wasn’t able to reproduce your issue.)
