RSS Feed not displaying on redirected domain

My ‘subscribe to this page’ RSS icon is not displaying in the address bar for some reason on my redirected domain. I have several WP installations on a single host and purchased additional domains pointing to those individual sites. If I pull up the site directly, I see the icon in the address bar just fine, but if I pull it up via the redirected domain, nothing displays.

So for example, WP is installed here https://www.site.com/me with a custom domain of https://www.mysite.com pointing directly to it. https://www.site.com/me displays the RSS icon in the address bar fine, but https://www.mysite.com does not.

Am I just overlooking something obvious here or is that just a limitation? Thanks for any help!