Very often I want to extend the duration of a chord by the current Grid Value. In the 1st image, for example, I’d like to simply select the end of the chord and press “Shift+Alt+Right” and extend it. But when the selected notes are of different lengths, you get something like the 2nd image, which doesn’t really work as I would expect. Why only extend one of the notes?
Interesting - when I go the other direction (shorten duration) it works. But lengthening doesn’t - I thought this was normal but now it seems like I’m running into some sort of bug?
Just a thought: possibly you added some shortcut to one of the commands in menu Write>Edit Duration which overrides (or is very similar to, so that you choose the undesired one instead) the factory shortcut Lengthen Duration by Grid value?
I ask because you said it happens “very often”…
(That said I have no idea which of those commands could give the result you are experiencing [prolonging just one note by a whole note value], so probably this is not useful)
To reproduce your example, I set the rhythmic grid to semibreve (whole note). One press of Shift+Alt+Right gave the result you showed. A second press of that key combination gave this: