ClearChildren before AddChildToVerticalBox doesn't work. Bug?

I reported this as a bug, but plz let me know if this is wrong.

With this:

UPROPERTY(BlueprintReadWrite, meta = (BindWidget))
	class UVerticalBox* VerticalBoxPlayerList = nullptr;

I have this test code in the NativeTick:

check(VerticalBoxPlayerList);
VerticalBoxPlayerList->ClearChildren();
UTextBlock* TextBlock = NewObject<UTextBlock>(VerticalBoxPlayerList);
check(TextBlock);
TextBlock->SetText(FText::FromString(TEXT("PlayerName")));
VerticalBoxPlayerList->AddChildToVerticalBox(TextBlock);

If you comment out the ClearChildren call, it works (but repeats, as expected).

Any mistake or workaround?

Thanks