RDP not working over ssl vpn

https://docs.sophos.com/nsg/sophos-firewall/19.0/Help/en-us/webhelp/onlinehelp/AdministratorHelp/RemoteAccessVPN/IPsecSSL/SSLVPN/index.html#configure-remote-access-ssl-vpn-connections

This link explains this issue. Under previous versions the SSL VPN global settings used an IP range for the "Assign IPV4 addresses". Under version 19 it uses a network IP subnet. You have to replace your custom IP host in Hosts and services, with a network IP subnet instead. Then change your SSL VPN firewall rule so that Source networks and devices have the new network IP subnet instead of the range. It worked for me. 

https://docs.sophos.com/nsg/sophos-firewall/19.0/Help/en-us/webhelp/onlinehelp/AdministratorHelp/RemoteAccessVPN/IPsecSSL/SSLVPN/index.html#configure-remote-access-ssl-vpn-connections

This link explains this issue. Under previous versions the SSL VPN global settings used an IP range for the "Assign IPV4 addresses". Under version 19 it uses a network IP subnet. You have to replace your custom IP host in Hosts and services, with a network IP subnet instead. Then change your SSL VPN firewall rule so that Source networks and devices have the new network IP subnet instead of the range. It worked for me.