Error ERR_EMPTY_RESPONSE on Ajax calls

I’m getting this error on all Ajax calls made during my acceptance tests using CodeCeption + Selenium + ChromeDriver + Chrome (all of those installed according to CircleCi tutorials):

Failed to load resource: net::ERR_EMPTY_RESPONSE

I just migrated from CircleCi 1.0 to 2.0 and the same test environment work fine on Circle 1.0

When I try to curl the url, I can see a json response, but my codeception/chromedriver/chrome is accusing an empty response