Audio Scrubbing not working at all?

I've been trying to figure this out for weeks, but audio scrubbing still won't work.
The audio works fine when I press the play button, but when I go along the timeline nothing plays, this is proving to be an issue as I have to add lip syncing to my animation.
I am a new Adobe Animate user so its possible I could have missed something, either way, help is much appreciated.