This has just started happening so I must have changed something. But what? I need help to stop going round in circles!
Would it be possible to include a screenshot, please?
Check your Formatting preferences pane. Is the text underlined in this box as well? If so, that’s where it is coming from! Those are your default settings for any new documents you create. Just toggle the underscore button in that window to get rid of it.
Thanks, that fixed it. And finding that gave me a good tour of the preferences available.