You can see this problem in the Defold editor too
I’m not sure what’s wrong, but I know I dealt with this kind of problem before in the past. Here is my tools for building icon.res files if that helps. I use https://iconverticons.com/online/ to make good ico files from pngs
icon.zip (545 Bytes)
Maybe custom icon is simply being ignored? The main exe doesn’t show custom icon either after being bundled.