I have tried the same scenario my database server is on Windows 10 Pro (VM) and pgAdmin4 is running from my MAC OSX. In the connection tab I have provided the IP address of Windows machine and in SSH Tunnel tab I have provided the IP Address and credentials of my MAC machine from where I will have to create SSH Tunnel. It works absolutely fine. Attached is the screenshots.
In your scenario you have provided the same IP Address in Connection and SSH Tunnel tab, that need to be change as per my understanding.
Note: I have disabled the firewall on Windows Machine.
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]@[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.