Location Personalization works on Staging/Alias domains but

Hey there, we are running Sitefinity 8.1 and noticed that our location personalizations only work on the domains we have setup as staging and aliases of the production server, but not the production domain itself. I've looked around the documentation as best I could, but could not find any mention of why this would be the case. The preview tool does show the correct content however. This happens regardless of the user being logged in or not.