Greeter sometimes fails to set Admin password on Stretch

First reported by u in https://labs.riseup.net/code/issues/12364#note-1

So the window opens in a weird location after clicking “+”.
Then I enter the password and click “Add”.
Then the option window closes and the option seems set, but it’s marked as “off”.
When i reclick a second time on the option I get a window bubble with the password and the password confirmation. I click enter and then it is set to on.

Parent Task: #11643 (closed)

Related issues

• Related to #12364 (closed)
• Related to #13447 (closed)

Original created by @alant on 12386 (Redmine)