I assumed the exoplanet child theme would automatically “enque” the master theme; it does not. A disabled default exoplanet master theme appears to load. My experience with child themes is that your current site will load at initial activation and then you are free to edit the bits you want to customize.
I am guessing the theme file name of “exoplanet child” should be “exoplanet-child” as recommended in the wordpress documentation. Without the “-“, it appears it cannot find the child theme file.
Are you using our Exoplanet Child theme from here: https://uxlthemes.com/docs/child-themes/? This works correctly. It has a functions.php file which correctly enqueues the parent and child stylesheets.
It is not the child theme file name which is important. The important part is that the parent theme template is correctly defined in the child theme’s stylesheet (style.css).
For example, you could create your own child theme for Exoplanet and name it “Seagull Twenty Two” with a directory name of “seagull-twenty-two” if you wanted to. To work as a child theme of Exoplanet, you would create the child theme style.css file with something like this:
Theme Name: Seagull Twenty Two
Text Domain: seagull-twenty-two
The “Template: exoplanet” part is the important bit that tells WordPress which theme is the parent.