Server group becomes unusable in PGAdmin4

Dear group,

I have a server group in PGAdmin4 and played with different servers and
different roles having different privileges. Somehow PGAdmin4 tries to
reopen the last used server connection when a new PGAdmin4 browser window
is opened. Now I'm in the situation where the last connection to a server
in my server group was stripped down to the point where it could not log
into the postgres server anymore. PGAdmin4 showed a brief "Internal Server
Error" message and I found it wise to stop / start the PGAdmin4 backend.
However, now every newly opened PGAdmin window is attempting to reuse my
last broken connection and does not allow me to open my server group to
e.g. chose a different server. I have also not found a menu entry like
"close all connections" or "do not reconnect to server at startup", to get
access to my server group again.

Any help is appreciated - where on my Mac is the last used connection
remembered? Can I remove that config?

Thanks, Michael

PGAdmin4 ( 3.1 )