ive been experiencing this issue for the last 3 or 4 weeks....
only started after use of an existing "working" file that work was lost on when c2 crashed on exporting ... i removed the extension from the backup file...got my work back, then the weirdness started to happen.
I highly recommend to create a new projectfile and use the .capx format instead of a folder before it's too late!
As I mentioned before, that did the trick for me and since then I didn't have to deal with this loss of data thing ever again.
Here are some things that you could do, to avoid this bug from ruining your progress:
> Pause any cloud-sync related programs while you work on your project and sync when you're done
> Disable Windows automatic standby mode
> Use a compressed capx instead of a project folder
If you want to be on the totally safe side just as I am, fully disable autosaving and do a "reminder" system.
I've added a global event which basically shows an alert to "Save your project!" after the window has been closed.
Even though it seems to work fine, I'm not going to trust autosaving ever again unless something is being done about it.