It's funny how writing these questions in the forum can make you think of new possibilities.

I was agonizing over this one for hours and then I finally figured it out as I was writing the question

If you use the Re-Login script step without dialog, and the user's password is expired, the re-login will fail. You can error capture for this but if you run the "Change Password" script step, it will activate for the currently authenticated user. In my case, the dialog wouldn't even show up if the script was set as an open script - go figure - this just added to my frustration in trying to find the root problem!

So what you have to do is script a new password through the "Reset Account Password" step, without the option to require user to change on next login... DUHHHHH

Boy do I feel silly.

Anyway, just though I migh be able to save someone else with my experience.

And now I've figured out why the dialog only popped up when the database was already running... when it ran in the open script I was authenticated as guest, so there is no password to change.

Wow. I wish there was an error for that.

Another thing to watch for - it appears the "Reset Account Password" step allows one to avoid the length requirements, so you have to script that in yourself.