In choral music different voices often double the same note. How do I select a particular voice from a doubled note? In this particular case I am wanting to move to the bass clef (using the “M” shortcut) a tenor note that doubles and alto note.
Try switching to Engrave mode and clicking the stem of the note you want to select, then switch back to Write mode and hopefully only the notehead you wanted is now selected. This isn’t ideal: we plan to make a number of improvements to how selections work when clicking, and one of them is to only select the topmost item by default, and require you to add a modifier to select the item(s) underneath.