Hi,
When Indicate Transpositions 
is active in the Key Editor toolbar, changing the MIDI Part’s Root Key 
in the Info Line or the Project Root Key 
in the Project toolbar doesn’t reflect the changes immediately in the Key Editor. The issue happens in both the Lower Zone and windowed Key Editor.
When transposing using the Info Line Transpose, or when adjusting the Transpose Track, the changes are reflected as soon as we tweak the settings, in real-time.
With the Root Key however, one of the following actions needs to be done in order to refresh the notes position :
-
Clicking into the Key Editor window,
-
Moving the Cursor in the Project Window (for some reason, doing so in the Key Editor doesn’t work),
-
Selecting another Event in the Project Window (including neutral objects like Arranger or Transpose Events) and selecting the MIDI Part again (selecting an Audio Event refreshes the notes instantly if the windowed Key Editor is opened),
-
Closing the Key Editor (including switching tabs in the Lower Zone) and opening it again.
-
Focusing the Project Window (if the focus was already on the Key Editor / Lower Zone only).
This behavior is very strange because as we change the Root Key, the Transpose field in the Info Line also changes to accommodate the key, but, we saw earlier that when tweaking the Transpose field alone, the changes are instantly displayed in the Key Editor, so why isn’t that the case when tweaking the Root Key, since the only thing it seems to do is Transposing via the Transpose field ?
If we analyse the issue further, we can see that after changing the Root Key, without doing any specific action listed above, scrolling through the Key Editor displays artifacts when the notes go beyond the view limits, they get erased, and when we scroll back the “new” notes have appeared. The notes also start appearing when placing the pointer where they are supposed to be.
The following animation shows this behavior :
So this proves it is indeed a real bug, where the GUI fails to refresh properly.