If you have a gradient in your export and you want to use it as a background image this doesn’t work.
I think I have found the source of the problem.
when you export a gradient it adds “:” in the id and I think on background image it doesn’t work. so if you just remove the “:” it works again
here is the file: Figma
here is the issue demo with fix: floral-sea-pj8tu - CodeSandbox