Join PC to a Windows Domain over a Lan - Lan VPN

I have a Windows 2016 Server. have a Windows 10 PC on a Workgroup. I want to join the PC to the Domain called [login to view URL] The PC is on [login to view URL] and the Server is on 192.168. 2.20. They are connected by a Lan to Lan VPN setup between two Draytek 2860 Routers. I can Ping the Server2016 From the PC both by IP address and Hostname But cannot join the PC to the Domain. I get the following error message:- ote: This information is intended for a network administrator. If you are not your network's administrator, notify the administrator that you have received this information, which has been recorded in the file C:\Windows\debug\dcdiag.txt. The following error occurred when DNS was queried for the service location (SRV) resource record used to locate an Active Directory Domain Controller (AD DC) for domain "[login to view URL]": The error was: "DNS name does not exist." (error code 0x0000232B RCODE_NAME_ERROR) The query was for the SRV record for [login to view URL] Common causes of this error include the following: - The DNS SRV records required to locate an AD DC for the domain are not registered in DNS. These records are registered with a DNS server automatically when an AD DC is added to a domain. They are updated by the AD DC at set intervals. This computer is configured to use DNS servers with the following IP addresses: 8.8.4.4 8.8.8.8 - One or more of the following zones do not include delegation to its child zone: [login to view URL] local . (the root zone)