I did some more testing and wanted to follow up with my original post in case others are still having issues.
I took my iPhone 6s to another unleashed network that a different iPhone 6s was able to use the app on. I was able to log into the other network without any issues and make changes.
I took my iPhone 6s back to the original site that was having problems, and I still can't log in. I set up a new unleashed network with two different APs. I was originally able to use the app to create the new network. Once the new network was setup, I couldn't log into the newly founded network. These two networks had their own separate firewalls and switches.
I grabbed my old samsung tab2, charged it and downloaded the unleashed app on it. I was able to log into the original unleashed network with the tab2 that the iPhone 6s couldn't log into. I'm curious to know why the iPhone 6s can't log into these two networks but can log into the other network without any issues.