How long to wait until license modal stops appearing?
Your production website shouldn't have been complaining about a different website using the same license key, as long as the license key is bound to the production websites domain name...
To get rid of the error, you can clear your Data caches. You can do this by navigating to Utilities &gt; Caches in your Control Panel, and there you can unselect all but Data caches. Once you clicked Clear Caches, you reload the page and the message(s) will be gone.