pgAdmin Unable to connect to server via SSH Tunnel (nothing in logs)

Using pgAdmin to connect to postgres via SSH Tunnel is giving me the
following error.

*Unable to connect to server:*

*server closed the connection unexpectedly*
*This probably means the server terminated abnormally*
*before or while processing the request.*

The only thing in the postgres server log is...

*2018-09-02 21:56:14.433 UTC [2613] [unknown](at)[unknown] LOG: incomplete
startup packet*

And the pgadmin4.log

*2018-09-02 17:19:42,934: INFO pgadmin: Failed to connect to the
database server(#2) for connection (DB:postgres) with error message as
below:server closed the connection unexpectedly*
* This probably means the server terminated abnormally*
* before or while processing the request. *

I have no issues connecting via SSH Tunnel using Datagrip, and I'm using
the same credentials\settings in pgAdmin ad DG...

I'm at a loss of what to do next to continue troubleshooting, as nothing
useful is in the logs.

Ubuntu 18.04 running PGSQL 10 on VirtualBox
pgAdmin 4 (3.2) running on Windows 7