I can't seem to get semitones in key editor

Hi,
When using the pencil, I can get the key editor to recognize whole tone but not semitones. This hasn’t been an issue in the past, so I must have accidently changed something.

Can anyone please explain what I need to do to have the key editor recognize the grey semitones?

In this screen shot you can see the G and A notes are added but I cannot get Ab (G#) to be entered.

Hi,

Does it follow the Chord Track or the Scale by any chance?

Thanks again Martin. I think you might be right there. It was working fine on another project.