Adobe Illustrator latest version - 26.0.03 - Export PNG lose transparent features - background shows gray in Google Chrome or Edge and 100% multiply features are lost. Tried all export options PNG PNG8, 24 and SVG.
As Ton mentioned, your PNG is fine. However, when you mention 100% Multiply, what do you mean by that? Transparency effects do not carry to an exported file format. They are only valid in the original program used to create the graphic.