VideoScribe only draws uniform, basic strokes. A uniform, basic stroke has a path down the centre and the width is determined by the weight of the stroke (usually in pixels). If you create an SVG containing brushed strokes or basic, non-uniform strokes the strokes will either contain a path around the outside which is filled, in which case VideoScribe will draw the outline of the stroke and the fill will pop in after or there is no path (or a path with no weight) and VideoScribe will add one around the outside.
It is possible to get VideoScribe to draw non-uniform and/or non-basic strokes with a trick that is probably best described in Mike Metcalf's forum post 'Making SVG Images Draw Well (2017 update)'. Mike is a long time VideoScribe user and SVG guru and covers everything you need to know about making SVGs in his forum post(s).
How do I create an svg file like the lines in this video picture?
How do I create a line that has a controlled pressure?