Could Audio Disappear from a Storyline?

Hello everyone--first-time poster, long-time lurker here. 

I was testing/polishing a course someone worked on last year in Storyline. The last edit they made was in May 2018, and shortly afterwards they left the company and the project gathered some dust until I worked on it in February 2019. 

I'm a big proponent of version control and integrity--when I was asked to make edits to this course, I saved them under a different name so that the original May file would remain as it was. This course was fully narrated and when I tested it, the narration was audible. 

Last week, I uploaded a SCORM package of this course to our LMS and no audio came through. I checked the SCORM package and there were no audio files to be seen. Most troubling of all, the edited version of the Storyline was missing all of the audio and so was the original, which was sitting undisturbed in its folder and showed the last change made was still in May 2018. 

Please let me know if I'm going a little nuts here, if it's possible for audio to evaporate from two files, or if I'm not seeing something obvious. My heart tells me that this, like most issues, can be chalked up to user error but I want to exhaust all my options first. 

Thank you very much!