It looks like Gatsby (in BUILD mode) returns some polyfills errors. I've tested it on clear gatsby project installation. For test purposes I just added console.log into pages/index.js and was assuming that the console.log message will be displayed. It is displayed but only in FF and Chrome. In IE I'm getting some polyfill error messages instead of console.log message. To be 100% sure I also explicitly defined IE11 in browserslist but IE11 should by supported by default anyway https://www.gatsbyjs.com/docs/how-to/custom-configuration/browser-support/.
There is the code base: https://github.com/gatsby-david/gatsby-polyfills-error
There is YT video where I'm showing the issue. https://youtu.be/d6w1VwDSXVs
Any help would be appreciated. Thank you,