VPN CANNOT BE CONECTED 6.37.5
I DOWNGRAEDED FOR MENY V 5.26 - 6.33 6.37 ALL THE SAM
Your post was very descriptive and informative that I can ID the problem with your setup…
Since you have tried multiple versions of code with the same result, then it is clearly a misconfiguration.
First of all freesstpvpn provide services for SSTP tunnels not PPTP, so I think it is obvious why your VPN is not working 
i traid vpn frome 4 month and it work fine but now not conect