No, it depends on the state of the parent when the child is created/added.
Basically a widget shows all its children when it is shown for the first time, but if you show a widget and then add children, they remain hidden until they are shown explicitly.
So what you are seeing is some kind of weird hybrid behavior, quite likely a bug.
I was mostly pointing this out as it would then not trigger your problem.
I.e. the weird behavior would normally not be observable.
Cheers,
_
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