adding an instrument with the right "scale"

Hi everybody,

4im not mother tongue English so I hope i'd be clear ;)

When we have a score done in a "scale" (for example not transposed intrument in A b Major : 4 b) and we add another intrument as for example Bb Clarinette, instead of 2b key (as it should be) Musescore think it is C Major and we need to chose the armature by ourselve.

But if we copy a line from an untransposed intrument it give as accidentals all the right alterations needed ...........

I don't know if someone else was confronted with that before, but wanted to tell it, as it can maybe me improved.... ;)

Thank you.
Lamardelmy,