Return to Site Link Not Working from Administration Area

I've tried locally with the same version and it's returning to the site, not the moderation panel.

This is an upgrade from 9.2 to 10.1, is it possible there is an outdated/deprecated override I missed in the upgrade process?

Was working fine in 9.2...

Please confirm you have your proper site root URL in Administration > Site > Default Site Url

Confirmed. Changing from HTTPS to HTTP and back has no change in behaviour.

Does it happen no matter the page you were on when you clicked on Administration?  If on the your site home page and you click on the pencil icon > administration, then go to Membership, what is the return link set to?

Yes, it doesn't appear to differ in behaviour from which page the pencil icon is engaged.

From Home>Pencil Icon>Administration>Membership the URL of the membership page displayed is:

https://community.[SITENAME].com/administration?returnUrl=https%3A%2F%2Fcommunity.[SITENAME].com%2F#_aptype=panel&_appanelid=f2902764-9ce1-4609-848f-5900b44a3ed2

The return link is:

https://community.[SITENAME].com/administration?returnUrl=https%3A%2F%2Fcommunity.[SITENAME].com%2F

Should that link be the actual returnUrl value? If I use the browser back button, I step through all of the steps of the administration page opening and the pencil icon administration panel opening too so is it possible that somewhere the administration URL is getting set as the referring page?

Yes, it doesn't appear to differ in behaviour from which page the pencil icon is engaged.

From Home>Pencil Icon>Administration>Membership the URL of the membership page displayed is:

https://community.[SITENAME].com/administration?returnUrl=https%3A%2F%2Fcommunity.[SITENAME].com%2F#_aptype=panel&_appanelid=f2902764-9ce1-4609-848f-5900b44a3ed2

The return link is:

https://community.[SITENAME].com/administration?returnUrl=https%3A%2F%2Fcommunity.[SITENAME].com%2F

Should that link be the actual returnUrl value? If I use the browser back button, I step through all of the steps of the administration page opening and the pencil icon administration panel opening too so is it possible that somewhere the administration URL is getting set as the referring page?

Unfortunately we're going to need some additional information that will require opening up a support case.  Please contact support and reference this thread.

http://support.telligent.com/