Typically it has to do with how the SVG is generated.

The baseline SVG I test against is this:
https://upload.wikimedia.org/wikipedia/commons/f/fd/Ghostscript_Tiger.svg

Compare that to yours and see if that helps.

Things to always check are:

1. Can you view your SVG locally in a browser outside of WordPress?
2. Are you defining a height/width? If not, try that.