When I open PL/SQL Dev I get "Oracle Logon" list with connections. Then PL/SQL Dev opens Workset I use. It doesn't matter which connection I choose Workset always opens with last connection used. I suggest to skip "Oracle Logon" when PLSQL Dev opens Worset or to change connection of workset to connection form "Oracle Logon" list.

We'll see if we can enhance this.

As a workaround you can specify the NoLogon command-line parameter. For example:

"C:\Program Files\PLSQL Developer 15\ Beta\plsqldev.exe" NoLogon