Welcome to our Forum.
I reckon you’ve tried to add some outlines to the scene through the Visual Settings? If so, please be aware that we are making use of a post-processing effect to achieve those outlines, which is why the output in Enscape will be different compared to the lines you see in SketchUp itself, which works on a geometry base, which means it also includes/displays lines on e.g. bevels (general geometry features) like in your case on furniture.
If I am missing something, or anything is unclear, let me know. Feel free to also share a screenshot with me in case you refer to something else here, or in case you’d like to receive further confirmation. 
The ability to display lines for geometry overall is also a feature request on our agenda. I can gladly forward your voice to product management as well so that they’re made aware of the further demand for this