Unfortunately I think it's only become clear to me now that preview mode does not work consistently for me. Which unfortunately means that all those times I thought I was doing something incorrectly in a patch (where no sound was being generated) may just mean that preview mode was being buggy.
I'm not particularly happy about this. Has anyone else encountered this and is there a solution? Right now all I can do is save my patch and deactivate preview mode in order to hear. I can not do live edits.