PgAdmin 4 - How to connect to database using unix socket via ssh tunnel?

Even though it might sound related to this question , it isn't, because I'm intreseted in the use of unix sockets instead of TCP/IP ones. However, I am unable to connect to a remote PostgreSQL database using unix sockets and an ssh tunnel with pgAdmin4. pgAdmin always claims a refused connection by the server and asks for a password, which makes me wonder. When sshing into the server and using psql a connection can be made just flawlessly using the unix socket (/var/run/postgresql). Is there anything special that needs to be set to allow such a setup, or might this even be a bug in pgAdmin itself? I'd appreciate any ideas to solve this problem without having to resort on TCP/IP connections on the remote side. I also post some screens from my current config: