Audio track(s) still playing even after deletion

Hi all,

Would like some advice on how I can remove audio tracks completely from my Storyline 360 project. 

I was refreshing a particular project, replacing its elements which include audio tracks. When I tried to delete the older audio track and insert a new one in all my slides, it ends up playing both audio tracks together. I've tried deleting the older track through the Timeline, and by deleting the speaker icon on the slide, but the phantom track continues to play. I've also tried to rename the newer Audio track but the double playing continues.

Lastly, I tried removing all audio tracks from the project altogether and saving it, close the Storyline program, and reopening it. The phantom track still plays.

Please advise. Thank you very much!