Missing merge requests - temporary fix for 8.3.4?

Our instance of GitLab CE has started showing the issue where it will not show a Merge Request button for new branches, issue is detailed here: https://github.com/gitlabhq/gitlabhq/issues/4100
In that thread it details a workaround regarding clearing the cache, cd /home/git/gitlab && sudo -u git -H bundle exec rake cache:clear RAILS_ENV=production
I don’t have a /home/git directory and bundle throws a command not found.
Is there a command I can use to get the same effect in 8.3.4 / do I need to run it from a new directory?

Thanks.

I have just upgraded to 8.4.4 and still have the same issue :unamused: