Using Alternate Intranet Address Causing Issues

I recently built a new internal network using WordPress called inSite. Our staff can access it just by typing in “insite” in their web browsers or by typing in the complete address: http://insite.xxx.edu while connected to our network or on the VPN. The General settings of the WP install are set as follows:

WordPress Address (URL): http://insite
Site Address (URL): http://insite

We just launched the site last week and all is good as long as you only type in “insite”, but if the full address is typed in (http://insite.xxx.edu) all the icons are missing and replaced with garbled text and a form doesn’t work on the home page. If you click on any other page (for instance Forms which takes you to “insite/forms/”, everything is fine and shows up, and if you click back to the home page where it was messed up, it is now correct and the address is just “insite”.

So as long as you only type in “insite” or “insite/xxx” everything is fine, but if you use the full address (http://insite.xxx.edu) to the site or any of the pages the icons are missing and forms don’t work but everything else is there.

So I don’t know if this has to do with what I have as the WP Address URL or Site Address URL in the General Settings or something else?? What do I check…how do I fix?

Also, I don’t know if this has anything to do with the issue, but our IT department redirected “intranet” to http://insite.xxx.edu when any of our browsers are opened initially. This is the way it was before only it went to “intranet”…now the browser shows “intranet” initially and redirects to the full address of insite).

I just cannot figure out what would cause the icons to be missing/forms don’t work but all information, page structure and everything else is there and fine just by using the alternate address. Any thoughts or help would be appreciative!