Hello efraims,
Thanks for reaching out to us!
I’m sorry you’re having difficulty in using our plugins. Hopefully we can get this sorted out for you as quick as possible.
As an initial step, after updating the slugs (to “eventos” and “evento”) try flushing the rewrite rules for your site by navigating to the settings -> Permalinks section of your WordPress dashboard and re-saving your permalinks.
If that doesn’t work, you can try our Testing for Conflicts procedures to see if the issue is a plugin or theme conflict that isn’t being used on the site you were able to get things working on.
Let me know if this helps.
Thanks!