Why is the ability to "create a test site" grayed out on configuration assistant?
Oracle Service Cloud Configuration Assistant on Oracle Cloud Portal
When a site is in the process of an update, some functionality is limited in Configuration Assistant. Creating and refreshing a test site is not allowed while an update is processing (potential concurrency problems could occur, etc.).
Keep in mind that cloning the production site when an update is underway means that the resulting clone will be on an older version than the production site, once the update is finished. A clone of the production site may be requested after the cutover post-process completes successfully.