Spontaneous corruption/swapping of slide notes?

I can't find anything about it now, but I have a recollection of having read someone talking about a similar problem before, so in case anyone else here has seen it...

I have a presentation with slide notes, from which I've used text-to-speech to generate narration audio. I rendered a draft version of the presentation as a SCORM object on our LMS, and then let the captivate file sit for a while.

The next time I opened it to make revisions, one of the slides had had its slide notes changed to match the notes of the next slide (so the original notes from slide N are gone, and slides N and N+1 now have the same notes). The generated narration is still there, and matches the original, now missing, notes so I know I'm not just crazy.

The file is on a Google Drive share and has been edited by a co-worker who added some quiz questions, but we were careful to never have the file open simultaneously, and manipulating slide notes in Captivate can be pretty clunky, such that I don't think there's any way the notes could have been swapped by a person on accident.

So, has anyone else seen this behavior like this? Is it a known issue, and has any guidance been found for avoiding it?