The .NET/C# driver no longer works in Xamarin applications deployed on Android Oreo (SDK 26) and later because of new security restrictions introduced in that version. Access to net.dns is no longer permitted and DnsClient.NET (one of our dependencies) requires this to look up nameservers for DNS queries. See DnsClient.NET issue #17 for more information.

DnsClient.NET's LookupClient has an override that allows explicitly specifying nameservers rather than dynamically looking them up. We could provide an option to override nameserver lookup in our driver and users could implement the Android-specific (or other APIs) necessary to configure DNS correctly for their device/environment.