2012R2 SSTP Cert CN does not match

Hello all,
I have been attempting to config SSTP on a two NIC box yet am running into the error of the cert CN does not match the passed value.........and when attempting to connect via L2TP, an error The machine cert cannot be found. The cert is generated and self signed via AD/CS, in the Personal and Trusted Store on the server and in the Trusted Store on the Win 10 client. I've followed instructions to the letter from two different sources, all has went well, yet I'm unable to get this to work. I'm fairly new to networking, have learned a TON! but still have a TON to learn! I am in the fog a bit about the NIC configs and that appears to be all that's left that I haven't redone a million times. I have no gateway listed in the internal NIC settings, just internal LAN IP, mask and DNS. The external NIC has a gateway set, IP, and mask, no DNS. What I'm most confused on is what IP should the external NIC have? I have a Cisco RV325 router and if I assign a "public" IP, the router will not forward to it or one to one NAT because the public IP is out of the LAN range. Not sure what to do here. Any ideas anyone? Also, the box is a Dell PowerEdge and I do see on boot that the BIOS has a remote access config. Could that be my issue or is that for something completely different?

Thanks, Ron