I am experiencing the same issue, but my reason for downgrading is completely different. I upgraded to Beta 2 from the latest iOS 10, and had a very peculiar bug that prevented me from fully activating my 10.5 inch iPad Pro. As soon as I upgraded, I noticed the new iOS dock appearing on the setup screen. I managed to configure it with little issue the until the Analytics screen , where the dock obscured the Accept button. I was stuck, was unable to complete my setup. I couldn't rotate the screen since it was locked and I couldn't access the control panel. No matter how hard I tried, I was unable to get past the analytics screen.After an hour or so, I decided to try and downgrade only to face the issue that the op and a few others are experiencing. This is it. I will never again install a beta. Since I live overseas, my only options is to wait a few weeks for a solution from apple, maybe trying DFU using a newer beta OR send my new iPad to Apple uncertain that the situation is going to be solved. Cautionary tale here folks.