I am also having the same exact problem along with my Mother. We both use Digis and live along the Idaho Utah border. Same as you, if I disconnect my wifi I can get AOL through my iPhone just fine but not going through Digis. I called and complained and Digis said it was not their probelm they were doing nothing to block AOL and no one else was having the same issue. I would say it is a Digis issue though.
I am also having the same exact problem along with my Mother. We both use Digis and live along the Idaho Utah border. Same as you, if I disconnect my wifi I can get AOL through my iPhone just fine but not going through Digis. I called and complained and Digis said it was not their probelm they were doing nothing to block AOL and no one else was having the same issue. I would say it is a Digis issue though.