How to connect to the second postgres server running as container on different than standard port in pgAdmin? – Docker

I am running two postgres servers as containers from docker-compose on different ports. In pgAdmin, only standard port mapping 5432:5432 is possible to connect. The second server mapped as 5433:5432 to avoid conflict is impossible to connect. Both server containers are running in separate internal network (intentionally), but both servers + pgAdmin are in the common external network. Other than that, all settings are identical.

docker-compose #1:

version: '3.7'

services:
    postgres:
        container_name: 'postgres'
        image: postgres
        volumes:
            - ../var/pgdata:/var/lib/postgresql/data
        environment:
            - PGDATA=/var/lib/postgresql/data/pgdata
            - POSTGRES_PASSWORD=password
            - POSTGRES_DB=firstdb
        networks:
            - netone
        ports:
            - '5432:5432'
networks:
  netone:
    external:
      name: workspace

volumes:
  postgres:

docker-compose #2

version: '3.7'

services:
    test-postgres:
        container_name: 'test-postgres'
        image: postgres
        volumes:
            - /var/pgdata:/var/lib/postgresql/data
        environment:
            - PGDATA=/var/lib/postgresql/data/pgdata
            - POSTGRES_PASSWORD=password
            - POSTGRES_DB=testdb
        networks:
            - test-network
        ports:
            - '5433:5432'

networks:
  test-network:
    external:
      name: workspace

volumes:
  postgres:

Both containers starts with success and running.

When I am trying to connect to the latter server, I am getting this in pgAdmin:

I have tried to change host to localhost, other ports, change db name, register under different servers groups, start both servers before pgadmin, etc. – no success. I am able to run interactive shell inside "problematic" server container and access postgres without any problem.
Running on Ubuntu. Appreciate any help.