[knot-dns-users] Additional section

Hi, We've been running Knot 1.6.3 as a slave server and it's been working well. However, I notice that a "dig" against this slave for a domain does not return an "ADDITIONAL" section, but the same query against another slave that runs BIND does return one. I couldn't find any Knot configuration directive that would control this. Is there something I missed or additional configuration needed elsewhere to make the ADDITIONAL info available? Thanks, Chuck