Subdomain confusion links not working

Hello.

I have domain.com which hosts the webpage for the business.
I have subdomain.domain.com which hosts phplist.

Suddenly entering verified links into places like webiew or unsubscribe or forward to a friend are going to domain.com and not subdomain.domain.com which causes links to break.

What is the standard configuration when we have a domain.com and subdomain.com with phplist hosted ONLY on the subdomain.com

This was working and as of v3.4.5 it now redirects all hard-coded links like:

https://subdomain.domain.com/something-here

to

https://domain.com or https://www.domain.com

Thanks!

SOLVED:

As duncan has stated when using a subdoman, the website address in the configuration in the settings must be the full domain name, including subdomain if that is there.

Even if it’s not a website. Perhaps it would be more clear if it was stated as not “website address” but “full domain of phplist install location”.