active directory reply url changes

how long does it take for changes to the azure portal to take effect ?
Im using active directory sign on and have set the reply url for my dev machine.
As Im using IIS express in visual studio it tags the port number onto the end of the url which works fine until I changed my project to use normal IIS then changed it back to IIS express.  This changed the port number so I updated them in the azure portal but I stll cant sign in, its looking for the old port number. I have experienced a lag when I update project files but this is ridiculous, I now cant sign in until azure 'decides' to propagate my changes