Can you share a picture of what you’re seeing, or perhaps a .zip file of your project? When you say subheading, do you mean the bit below the project title that appears as “1. Flow 1” in a new project? If so, that’s called a flow heading - by default, it shows the flow number (e.g. "1. ") and the flow title of that flow. It does this using tokens.
You can change flow titles in Project Info too - just select the relevant flow in the list on the left, and amend the details on the right as necessary.