Realyl impossible to know. You have not even mentioned in what exact program you are importing your SVGs, so we can't check what the specific requirements are. Similarly, of course you would have to provide screenshots and ideally a test file of your artwork to check the SVG code vs. the appearance. perhaps you are simply using an unsupported feature that may require a different approach or you need to experiment with the SVG export options. Again, realyl impossible to know at this point.