AWS amplify full stack demo build error at geo/lib-esm/util.js:

was playing around going through this AWS amplify tutorial (auth,S3, graphql setup)

https://aws.amazon.com/getting-started/hands-on/build-react-app-amplify-graphql/module-five/?e=gs2020&p=build-a-react-app-four

all working locally but fails CI (and local npm run build) due to the following error… any ideas boys and girls?

node_modules/@aws-amplify/geo/lib-esm/util.js: symbol.charCodeAt is not a function
    at Array.map (<anonymous>)
    at Array.forEach (<anonymous>)

running these versions :

"@aws-amplify/ui-react": "^4.0.0",
"aws-amplify": "^5.0.1",