Why does widget_visibility.Hidden not work!

OnPlayerSpawned(Agent:agent):void=
if(not CanvasPerPalyer[Agent],Player:=player[Agent],PlayerUI:=GetPlayerUI[Player]):
CustomCanvas := CreateProgressUI()
PlayerUI.AddWidget(CustomCanvas)
CustomCanvas.SetVisibility(InVisibility:=widget_visibility.Hidden)
if(set CanvasPerPalyer[Agent] = CustomCanvas){}