The use case is following the steps to reproduce, happens every time regardless of user widget and regardless of which island I have open in UEFN, also happens for a friend and the only way to get around it is duplicating a widget that has working message variables, duplicate the message variable to get more and you cannot change the names on them or else the field disappears
The default value for messages in a widget was purposefully hidden because we do not support default values for messages there at the moment. You must specify the message in your verse code when instantiating the widget etc.