Key signature change not reflected or applicable in part if multi-measure rests amount to first system

1. Open attached score (produced in 1.3).
2. 'File'>'Parts…'.
3. 'New All'.
4. 'OK'.

5. Change key signature of full score (e.g. C♭ major).
6. View Keyboard part.

Result: Key signature is still D♭ major.

5. View Keyboard part.
6. Change key signature (e.g. C♭ major).

Result: Key signature isn't changed.

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