MusScore version 4.5.1.25....
Support:
On the previous versions it was possible to define different "Key Signature" to different instruments of the same score. Selecting Key signature for one of the instruments, changes immediately the key signature of the others to the same signature.
Is there a solution?
Comments
It's still the same. You need a local key signature. See https://handbook.musescore.org/notation/pitch/key-signatures
Or perhaps you need to set up your score with the correct instruments so that transposing instruments have the correct, different key signature. See https://handbook.musescore.org/basics/setting-up-your-score And make sure you are viewing with concert pitch deselected (bottom right of window).