When the Label parameter of the TelerikMaskedTextBox is not defined, the Width is applied to the input of the component. However, it should be applied to the span holding the component.
A couple of workarounds:
- You can define the Label parameter of the TelerikMaskedTextBox. In this case, you will not be facing the mentioned bug and also will not have to separately define a label tag
- You can set the Bootstrap class "form-control" to the TelerikMaskedTextBox through its Class parameter and remove the Width parameter.