on the panel_2 form’s success event call the panel_1 serverconnect like this:
<panel_1-route-name>.<panel_1-server-connect-name>.load()
since panel_1 is already in browser memory loading it’s server connect is possible.
in case there is a scenario when panel_1 was not in memory, then this server connect load will fail.
however, when the user clicks on the panel_1 link to open that page - the server connect on panel_1 would auto load (? i guess you are auto loading that server connect as it has to display the list of items) and updated list will be fetched from DB.
hope i have understood your problem correctly and given relevant answer.