Unable to change realm server option to Automatic (first to join session).

I am able to change the region to all the countries, but when I try to change to Automatic, nothing happens. It was originally on Automatic, but I changed region manually at one point and now I can't change it back to automatic. I tried temporarily closing the realm, but that doesn't work either. I’ve tried switching to other regions and then automatic again, but nothing seems to be working.