Tools> Transpose> Use single #and ♭ not working

Hi there, my score has double sharps on some of the notes and Tools> Transpose> Use single #and ♭ doesn't seem to do anything. I have tried selecting everything before clicking on this setting too but still to no avail. Short of clicking on each double sharp through the chart and typing 'J', is there a quicker solution for this?
It happens on various instruments be they concert or brass and I've tried inputting the single sharp flat setting before entering notes onto the chart too and again it makes no difference. Also tried cycling through all the keys but the double sharps remain!

Any help solving this gratefully appreciated!