ACF - Field Group "Location" settings stop working if category slugs used in the conditions change

Overview of the issue

ACF Field Groups set to display if Post Category {Some Condition} {Some Category} can stop displaying properly if the slug for {Some Category} is updated after the Field Group is created.

Workaround

We have received a few reports about this issue, but it is not related to WPML and can be reproduced even without WPML enabled.

This is due to how ACF stores those conditions for categories. It uses the slugs, rather than IDs as it does for Post IDs.

You can work around the issue by following these steps:

1. Back up your website completely
2. Open the Field Group
3. Check the Location widget and correct the Rules
4. Save the Field Group by clicking Update