Cucumber tests fail randomly

I have some Cucumber Scenario that are failing randomly both on local machine and Codeship (for Continuous Delivery). Running them individually or all together makes no difference, still pass and fail with no (identified) reason.

In detail, looks like Capybara is unable to find an element on the page after the 'Continue to next page' is clicked. As suggested here I've updated the default_wait_time to 10 seconds and even tried to put some sleep() with no success.

I've also seen that somebody had a similar situation (see here) and fixed updating the capybara-webkit. So I've updated cucumber, selenium and poltergeist gem (working in Ruby) but that didn't fix the problem either.

It's worth mentioning that last time we pushed code in production these tests were passing correctly, both locally and on Codeship. No other release has been made after that so they started to fail while the code was already pushed in production. We explored some possible link with not-updated dates but looks like is all ok on that front.

Any suggestion? Thanks in advance

Environment: Ruby on Rails 2.0.0p598, Capybara 2.6.0, Cucumber 1.3.20, Cucumber-rails 1.4.2, poltergeist 1.8.1, selenium-webdriver 2.49