My inventory has completely disappeard

Site URL: https://johnsipher.org/music-for-purchase-1

I'm updating my website in anticipation of a new release, and my inventory keeps freaking out and disappearing, only to reappear again an hour later or so.  This has been happening for the last day.  My add to cart buttons disappear, even though they're toggled on, and when I go  to my inventory page, there's nothing there.  Is this happening to anyone else?

Have you quit and relaunched your browser? Your computer? Does the problem persist?