Elasticsearch not working with data loaded by liquibase
Try my project here:https://github.com/geraldhumphries/generator-jhipster-elasticsearch-reindexer
This generates a service that allows you to sync Elasticsearch with your database. It's very similar to your implementation but it needs to be run manually by an admin user and is accessible through your API. In your case, you just need to run it once manually while your application is running and it will index the 30,000 rows you inserted using Liquibase.
You can modify the generated service to remove indexing for every other entity. There is a planned feature to allow you to ignore certain entities.