1. Verify Relationship Data

Ensure Lessons are Linked to Courses:

1. Edit a Lesson: Go to the WordPress admin dashboard, and edit a Lesson post.
2. Check Relationship Field: Make sure the Course field is populated correctly. The lesson should be linked to a Course.

Test with a Specific Course ID:

1. Manually Check Data: Use a plugin like WP phpMyAdmin to view the wp_postmeta table.
2. Look for Meta Key: Check for entries where the meta key matches your relationship field. For example, if your relationship field is jet_engine_relation_courses_lessons_course_id, find rows with this key and verify they have correct values.

2. Confirm Meta Query Settings

Check Field Key/Name:

1. Identify Meta Key: Go to JetEngine > Relations and confirm the exact meta key used for storing the relationship between Courses and Lessons.

Meta Query Configuration:

1. Go to JetEngine > Query Builder and open your custom query.
2. Meta Query section:
   • Field key/name: Ensure it matches the meta key found earlier.
   • Compare: Set to =.
   • Value: Use a dynamic tag for Post ID or test with a specific ID.
   • Type: Set to NUMERIC.

3. Test with a Static Query

Set Static Post ID:

1. In your Meta Query, manually input a Course ID in the Value field (e.g., 123).
2. Save and Refresh: Apply changes and check if lessons appear for this specific course.

4. Review Listing Grid Settings

Check Query Binding:

1. Go to JetEngine > Listings and edit the Listing Grid for Lessons.
2. Ensure the grid is bound to the correct Custom Query.

Create a Simple Listing Grid:

1. Create a new Listing Grid without complex filters.
2. Use a basic configuration to test if lessons are being listed correctly.

5. Debugging

Enable WordPress Debugging: