Can’t Convert Theme with WPBakery?

Hi guys. Newbie here.

I just discovered SiteOrigin and Page Builder. Looks awesome.
However, I have a site I just built using a theme with WPBakery visual composer. When I try to use Page Builder to change an existing page, it asks: “Would you like to copy this editor’s existing content to Page Builder?” When I click “yes” the page then shows all or mostly blank. Page Builder doesn’t convert the prior VC elements into PAge Builder elements/widgets. It just copies all the prior code into one single new editor widget.

Is there a way to convert properly?
Am I expecting too much?

Thanks,
-Dan