I am not sure if it is a bug.
It doesn't matter if I set the Visible (Common Properties) value to True or False, it will be Visible when the app starts. I only tested in B4J.
We need to set the Visible to False by code in B4XPage_Created.
Private Sub B4XPage_Created (Root1 As B4XView)
Root = Root1
Root.LoadLayout("MainPage")
B4XTable1.AddColumn("Sample", B4XTable1.COLUMN_TYPE_TEXT)
B4XTable1.Visible = False ' setting in Designer has no effect
'Pane1.Visible = False
End Sub