That is happening because you have enabled Redirection for the affected product(s). That setting is typically used as a form of digital delivery, to grant buyers access to a private URL where you are providing online content they have paid to view, so we issue a link to grant access to that content.
It appears your products are using a Redirection URL which is just the URL of a general thank-you page, and this is the same as the Common Thank-you Page URL you have entered in your Seller Admin > Account Preferences screen, so you should probably just edit your products to un-check their Redirection settings, and that will remove the message you referenced above.
