Output image being cropped

[ericman314]

I'm having trouble generating a png image correctly. The output png image is the correct size, but the figure is being cropped to 400x300 no matter what output size I request.

Here is my code. In this example, imageWidth is 479.

let pngBuffer = await svg2png(Buffer.from(svgString), { width: imageWidth })
await fs.writeFile(filename, pngBuffer)            

The first line of svgString is:

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" preserveAspectRatio="xMinYMin meet" viewBox="-80.9714977388259 -166.4741201283966 287.97746576236545 251.25923173892323" width="100%" height="100%">

The output image size is correct at 479x418, but only pixels in a 400x300 rectangle are drawn.

The output image should look like this:

What am I doing wrong?