Homepage won't display, other pages do.

New to multisite. I just installed wordpress multisite on my Synology NAS with subdomains, including domain mapping plugin. Everything works except when I go to the root URL of any of the sites I add (i.e https://www.example.com) I do not get the sample page for that site, it maps back to the webroot of the site and displays a blank page since there are not webpages in the webroot (just wordpress install) However, if I add new pages to the site and click the link to visit those pages, they all come up perfectly. So I can’t figure out why the root home page doesn’t resolve to the correct default home page for each site.

second question – should there be a subfolder created for each new site. When I create a new site from WP, it says it created, but I don’t get any new folders created. It’s confusing to me, b/c I’m used to running web server with virtual hosts, each site has it’s own folder and I use HTTP headers to map different domain names. With WP Multisite, do I not need separate folders for each site? Is this why root url for each site isn’t mapping back to the same webroot location where WP is installed