I had defined several custom table styles.

They used to appear in the Gallery under the heading "Custom Styles."

Suddenly, they disappeared, and so has the heading "Custom Styles." So I can't use them anymore.

I tried defining them again. Once again, they don't show up in the Gallery.

And yet I know they're in there. Because if I define yet another new custom table style, the drop-down menu "Style based on:" includes all the names of all my custom table styles.

How do I get these custom table styles back in the Gallery? Or is there some other way I can apply one of these custom table styles to a table?