pdq link client not connecting ...

Hello. Not sure if anyone can help but thought I'd report my experience. I was hoping it would be relatively simple with this PDQ Link installer but this is now starting to get beyond my knowledge limits. Its a little frustrating but enjoying the challenge and learning new stuff so will keep trying for a bit as I still have some things to try and docs to work through.

PDQ Link appears to install on the server and pc okay - 2016 vm + W10 1809. Everything gets a green tick. Wireshark confirms port forward is working and traffic is routing correctly between the server and client. Current server is now a fresh 2016 VM after being unsuccessful with two existing 2016 vm's - on on which server installed okay but client not connecting. Decided to try a fresh vm to eliminate anything that might be causing problems. 2016 server and client are domain joined and I'm logged into server with a domain administrator account. PDQ Link has been setup with the DHCP option.   

Wireshark shows that client is constantly trying to connect (see log below) but deciphering meaning from the packets is a little beyond my current knowledge. This is confirmed by the client application eventlog filling up with error event id 20227 which reports error code -2146762481. I'm yet to figure out exactly what this means.

I'm about to re-run the PDQ Link setup on the server and choose the static option. I'm also going to try -recreating the certificate. Beyond that I will start reading docs to understand better how ras etc. works and perhaps where to focus troubleshooting. Any tips or pointers to help me focus on the right areas would be greatly appreciated.

Thanks.

Repeating Wireshark block from server end:

No. Time     Source    Destination Protocol Length Info
22 11.185312 client-ip server-ip   TCP      66     61474 → 443 [SYN] Seq=0 Win=64240 Len=0 MSS=1452 WS=256 SACK_PERM=1
23 11.185413 server-ip client-ip   TCP      66     443 → 61474 [SYN, ACK] Seq=0 Ack=1 Win=8192 Len=0 MSS=1460 WS=256 SACK_PERM=1
24 11.194994 client-ip server-ip   TCP      60     61474 → 443 [ACK] Seq=1 Ack=1 Win=66560 Len=0
25 11.196901 client-ip server-ip   TLSv1.2  210    Client Hello
26 11.198686 server-ip client-ip   TLSv1.2  1262   Server Hello, Certificate, Server Key Exchange, Server Hello Done
27 11.211656 client-ip server-ip   TLSv1.2  147    Client Key Exchange, Change Cipher Spec, Encrypted Handshake Message
28 11.212212 server-ip client-ip   TLSv1.2  105    Change Cipher Spec, Encrypted Handshake Message
29 11.222819 client-ip server-ip   TCP      60     61474 → 443 [FIN, ACK] Seq=250 Ack=1260 Win=65280 Len=0
30 11.222854 server-ip client-ip   TCP      54     443 → 61474 [RST, ACK] Seq=1260 Ack=251 Win=0 Len=0