Elastic Search Not Reflecting Database Changes

Hello we are using Elasticsearch version 7.16.2. We having synced our Elasticsearch with database using listeners. Usually the Elasticsearch reflects the database changes within no time but once it happened that it took days to reflect those changes. Can anyone help what could be the reason ?

Exactly how are you doing this?

we use java in the backend as programming language. we have a class declared with @EventListener annotation inside that we have logic of re-indexing the elastic index to reflect new changes each time an event happens. Also we register database table which we want to get synced with elastic for database change notification feature.

I would suspect the isue then is with this mechanism unless you see anything in the Elasticsearch logs indicating e.g. that you are running out of disk space and indices have gobe read-only.