My Liferay installation has been flawless for months. However, recently, I noticed that the main navigation links generated by $nav_item.getURL() are including the private group URL (i.e., /group).

For example, here are what the links should be and have been for a while:
http://localhost:8080/link1
http://localhost:8080/link2
http://localhost:8080/link3

Recently, they changed to:
http://localhost:8080/group/mysite/link1
http://localhost:8080/group/mysite/link2
http://localhost:8080/group/mysite/link3

I did not create any new sites or make any configuration changes that I'm aware of. All the links above work, but I do not want the "/group/mysite" in the URL. I also noticed that when I'm editing a page in the control panel, the friendly URL field does not show the "/group/mysite".

Any ideas what might be going on? I'd really like to avoid a rebuild of the site.