Chord symbol shortcuts not working

See the Handbook section Chord name . There are different chord symbol styles available, and you need to choose the one that best matches how you like to abbreviate your chords, and then enter your chord symbols according to that style. But even so, MuseScore can only render chords it was pre-programmed to recognize. The chord symbol you list is not among them. There *is* a "69" chord, but not that in conjunction with major (or minor) seventh. In some of the predefined styles, "69" chords that are recognized are rendered smnall; in others they are not. As for "m" versus "M", none of the pre-defined styles recognize "M" for major, but several recgonize "m" for minor, so they will "correct" it for you.

Bottom line: choose a chord style well, then enter chords symbols the way it wants you to., You can use the Chord Chart plugin to generate a list of all the chord symbols recognized by any given chord symbol style.

For the next major version, things get much more flexible. You won't have to preselect a style just to be able to type what you want - although you will still be able to select between standard and "jazz" rendering styles (the latter using the MuseJazz font, superscripting, etc). I just tried, and "Ab69M7" is recognized nicely, even though it never would have occurred to me to preprogram that symbol.