My workaround was to export the icon as SVG and use Inkscape app to do the trick.
While Figma failed to convert my github icon, the conversion was pretty straight forward with Inkscape
Countless times Inkscape or GIMP (both open source) saved my skin where Illustrator, Sketch, Photoshop or Figma failed to perform a specific task. Most of the designers tend to ignore or be unaware of these projects so I thought sharing this info might be helpful.
Having said that, while the I understand that there are great technical challenges to solve this bug (after all, I’m a software engineer as well), I find it a bit disrespectful that this issue has been marked as solved, @dvaliao (no offence intended). The UX is clearly awful and suggesting to redo the work manually as the “solution” is not right, especially for paying customers. You said it: “This is a long standing bug”, so if it’s still a bug, it’s clearly not solved so this topic should remain open. But that is only my opinion @dvaliao and I understand that there are other priorities in the backlog and pressure to not keep a 2+ years old bug wide open in the community.