Redux not updating properties in IE11. This problem is because of IE11’s poor ES6 suppport. I found that you need to polyfill both Promises and Object.assign.
As for Babel, it’s probably due to Babel transpiling only non-standard code to standard code. Most browsers already implement Promises/Object.assign by default so I guess the newest Babel versions doesn’t need to transpile it to ES5 code anymore.
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