No. The main domain of the website is the domain name that you entered into the domain field of the website and the main domain is listed first.
Ah, I see. So, all I need to do is add the www to the main domain name for the website and the problem will be solved.
My only other question is whether or not including the www subdomain in the main domain name will change the behavior of either a) setting auto-subdomain to "www", and/or b) setting SEO redirect to "domain.tld -> www.domain.tld"; does the main domain value have any effect on the behavior of those settings?
Thanks for clarifying, Till!