The "Wait until launched application is started before continuing" option can only detect when an application has started, not when it has completed loading (as the latter differs per application; This is a Windows "restriction").
You'll have to add a pause using the "Pause >" button context menu (or the "Add Pause" entry in the action list's context menu), to wait until the first application would normally be loaded (you'll have to time that manually and adjust accordingly).
If the application opens a different window when it's done loading, you could also add an idle loop that checks for the existence of said window before continuing (This is an advanced option, so you may want to try the pause first).
E.G.
Run application 'notepad'
Set Text [~~targetWindow] to 'Untitled - Notepad'
Start Loop While : [{WINDOWEXISTS:~~targetWindow}] Does Not Equal '1'
End Loop
Write [Blue] 'Application window has appeared' to log
Note that the window appearing does not mean the application will correctly receive input yet (if you're sending keypresses to it, for example), so you'll still want to add a pause after the idle loop, too.
For more information, press F1 while VoiceAttack has focus to open VoiceAttackHelp.pdf