We ejected from react-scripts and so could not simply upgrade the package.json entry to fix this.
Instead, we did this:
1.) in a new directory, create a new project -> $> npx create-react-app foo-project
2.) and then eject it -> cd ./foo-project && npm run eject
3.) now copy the files from /foo-project/config into the config directory of our main app and fire up your dev server
hope this helps others in a similar bind.