eSign for iPad Access Token error

I'm attempting to use Adobe Sign for the iPad. I have Adobe Sign via the browser on another device that works. I use Adobe ID to sign in to the app (because I do not have an individual Adobe Sign account). Once signed in, it requests that I allow the iPad access. I tap Allow Access and up pops the following error.

Unable to sign in to Document Cloud. Error Domain=NSURLErrorDomain Code=-999 "cancelled" UserInfo={NSErrorFailingURLKey=https://<ourDomainName>.com.echosign.com/oauth/token,NSErrorFailingURLStringKey=https://<ourDomainName>.com.echosign.com/oauth/token,NSLocalizedDescription=cancelled}

I need to know what this specifically means so that I can resolve the error. Would there be a reason that I can use Adobe Sign on my computer, but not the iPad?