Tagging Facebook Pages From Other Pages

I am the admin of 3 pages and when I try to tag one from another, it doesn't show up in the drop down. I only became admin of the untaggable page to assist in fixing the problem, but even before I became admin, I could not tag the page from my community pages, but I could from my personal page. I've done Google searches and read plenty of blogs and forums and the #1 solution is to select a web address such as facebook.com/yourbusinessnamehere, and we have done that but it still isn't working. We also can not edit post from mobile devices.