pgAdmin4 ssh tunnel configuration

I can't get the ssh tunnel configuration that I use with pgAdmin3 to work
with 4. After I enter the
parameters and click "Save" I immediately get a dialog box that says:

Connection to the SSH Tunnel for host 'my-postgres-server' has been lost.
Reconnect to the database server.

I'm using identity file authentication. In pgAdmin3 it wants both the
private and public key files. In pgAdmin4 only the private file is
specified. Otherwise everything is the same.

The error is instantaneous and the server is 1000 miles away, so it's not
even waiting for a tunnel to get opened or a database connection to be
attempted.

Any suggestions?
Thanks
--
Richard W. Greenwood, PLS
www.greenwoodmap.com