If you completed a Location Clone from one Clover account to another and some items are now grey-out and are unable to sell, this may be because the Clover service plans are not the same. Some Clover service plans allow for specific items to existing in your Clover inventory.
An excellent example is that you will need to have the Register Clover Service Plan to use Item with Variants with the Clover Point of Sale. Without the Clover variants functionality, your device will not have a way to display items with variants.
You can view more about Clover Service Plans here: https://www.clover.com/help/compare-clover-service-plans/