To reproduce: Set RadLabel.AutoSize = True, RadLabel.MaximumSize = (100,0). When set the Text property to a string with width wider than 100, the text won't cut off (when TextWrap = false) or wrap to a new line (when TextWrap = true).
Workaround: Manually set RadLabel.LabelElement.MaxSize = New Size (100,0). The behavior of the control becomes normal. But it is not convenient as we have to set a large amount of label controls in the code behind rather than to set them in the designer.