VfxWidgetGroup. When rendering to a Stage with offsetted viewport - actors are clipped by viewport offset.

[DirolTerminator]

Not sure if it can be repeated on a clean project, but I'll leave it here for further research and testing.

1. Correct rendering

public void render() {
		stage.getViewport().setScreenBounds(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight()); 
		stage.getViewport().apply(true);
		stage.act(Gdx.graphics.getDeltaTime());
		stage.draw();
}    

Result is:
https://imgshare.cc/3juuc570

2. Incorrect rendering

public void render() {
		stage.getViewport().setScreenBounds(30, 20, Gdx.graphics.getWidth(), Gdx.graphics.getHeight()); 
		stage.getViewport().apply(true);
		stage.act(Gdx.graphics.getDeltaTime());
		stage.draw();
}    

Result is clipped actors by x=30 and y=20 respectively:
https://imgshare.cc/3pntjv8d

Actors which got clipped are specifically VerticalGroups, nested inside Window (all instances of WidgetGroup, consisting of other child actors) if thats matters. It seems that renderer applies viewport offset to each WidgetGroup separately.