React components not being rendered when running feature specs on circleci

I have a small Rails project and the front-end is built with ReactJS.
I have some feature specs, and they work fine locally, but fail when running on circleci.

My last attempt can be found here:

And this is the link to the failing build:

The HTML page is rendering fine, but the react components are not.
Would someone know what I could do to fix this?

Many thanks!!

oh, and this is my circleci config: