When a curve is converted to a text path, the stroke of the curve is still present on the the text path. In order to remove this stroke, the Text Frame Studio is needed. However, the contextual toolbar does not show the button for the Text Frame Studio. Combine that with the fact that the Designer persona in Publisher works differently with regard to keeping the stroke than actual Designer (which is a bad idea), this confuses the user when he wants to remove the stroke.
Here is a video demonstration in case it helps:
missing_button.mp4