ForceLayoutPrepass does not help in this scenario. Another note, this only manifest when the widget is first constructed. Further updates handle desired size well.
Yes. This seems to be related to the widget being constructed. If you can construct ahead of time and later hide / show (rather than add / remove from viewport, which would trigger construct), it seems to behave pretty normal. And that’s without Delay or Prepass.
I’m pretty sure I was having this same issue well after a widget was constructed. My experience was that the issue seemed related to the first time the text is rendered with auto-wrap. My hacky workaround is to first display a bunch of spaces (as in spacebar presses) before trying to render the text I wanted to not flicker.