Troubleshooting 404 errors with published items in different CMS collections

The community member is experiencing an issue where all their pages under two different CMS collections are leading to 404 errors, even though the items are published. Another community member suggests that the issue may be related to a setting being switched off. However, a second comment indicates that the issue seems to be specifically with the collections that have an integration with Letterdrop, and the community is seeking insights on this.