Tablature - Moving Fret No to Another String ?

After allowing Cubase to automatically convert my notation to tablature, I am now trying to reposition the fret numbers to my preferred position on the fretboard.

When I right click on a fret number there are two options ‘Move to String’ and ‘Move Note’. The Move Note item has two options ‘Move to next string’ and ‘Move to previous string’ both with a plus or minus symbol next to them. However if I select a fret number (so its highlighted) and press + or - nothing happens. The only way I can move a fret number to a different string is by using the ‘Move to String’ option but is a bit laborious when moving lots of frets throughout the song.

Ideally it would ne nice to use the right arrow key to select a note then + or - to move the fret number to a different string, but its not working - what am I doing wrong ?