Fix Steam popup upside down??

As you can see in the screenshot of my game below the steam pop up at the top-right of the viewport is upside down and mirrored.

I'm using Greenworks 0.71 for NW.js 0.71.0 and the relative Steamworks SDK: 1.50. In the export I opt the "Export for Steam" check.

Do anyone know how can I fix this kind of issue?

Thank you guys!