Master slides Randomly Changing

The Storyline file is not a saved file; it is a series of zipped, saved files. Any sort of network hiccough, buffering pause, or stray quark flying through your network during the compression phase can cause enough of a problem  to introduce corruption. That's why local saving, then uploading after the zipping is done is safer. To be fair, MS uses the same scheme for office files, and they seem to be much more robust.

I would suggest that it might help you to go through the project, and reduce it to only one master. It is very easy to end up with tons of Masters, and I don't think that load aids good program function.