When you draw a text frame on a body page, you are prompted for the number of columns and the gap between them. However, FrameMaker does not assign a flow tag and does not connect the text frame to existing text frames on the page.
To use the new text frame as part of the document’s text flow, connect it to the flow.
If the new text frame is the first one in the flow, also select Autoconnect so that new pages are automatically added as needed.