I installed the xblog pro and child theme 1.2.4 from 5/14/20. The child theme shows as “current.”
With the new WordPress release 5 my WIDGETS are gone. They still work in the front end (“legacy widget”) but in my back end all I see is a “Block areas” list showing a few settings. There is no way to see the page where I can CHOOSE and install widgets. There is no LIST OF WIDGETS.
Maybe I panicked too soon. Your theme has the right widget areas. I was not able to insert an item because the PLUGIN is not yet updated to WordPress 5.1. The problem of “experimental – legacy” apparently refers to plugins, not to widget areas of your theme. I will inquire with the plugin vendor. Your theme is still serving me very well.