I am trying to get Routing and Remote Access Server to work and had put in a lot of time to find out why I can't establish a successful connection for a machine tethered from my iphone.  I have setup an assimilation network using  Essential 2016 and my other desktops/laptops to connect to it but I am pretty much stuck. 

The Essential server is set up with RRA service and I used the Dashboard to install the service.  I used this guide to install just the RRA service and not IIS: 

https://www.lukasberan.com/

port 443 is opened on router

I am getting this error ID 22 from event log on the server:  The SSTP service could not be configured to access incoming connections.  The detailed message is provided below.  Correct the problem restart the SSTP service.  Access is denied.  

I check AD and grant each account to access incoming RRA connection.

I have tested the vpn connection (tethered to LTE wireless network) and it looks like it is trying to verify the username but it throw out an error:

Error 800: The remote connection was not made because the attempted VPN tunnels failed.  The VPN server might be unreachable.  If this connection is attempting to ue an L2TP/IPsec tunnel, the security parameters required for IPsec negotiation might not be configured properly.

Please help.