Those are a strokeless fill. (Obviously there’s a vector path associated with it, but there is no Stroke Color assigned to it, so the interface ignores the path.
On your original, in Inkscape, select the text, click on Path > Object to Path, and then click on Path> Stroke to Path.
Inkscape has a two step process that’s required because of the way it’s set up for handling Bezier Curves. (Described in the tutorial below, if you want to understand more about it.)
And single stroke fonts are described here: