When the Zotero connector detects the presence of a proxy prefix on a web resource (such as when you access Trexler Library content from off campus) it will show a yellow pop-up bar at the top of the browser window stating that a proxy has been detected and asking you if you'd like to enable proxy redirect.
If the proxy happens to be for a different institution or be in error, then enabling this could re-direct you in error every time you visit the vendor involved.
Note that if set up properly, Zotero can assist you with proxy redirects the way it should... but be sure to set it up properly to avoid errors!
See the Zotero documentation for instructions on proper use and set up.