Hi Anand,
I would first suggest running a few maintenance tasks that can help to resolve common issues - most importantly, rebuilding the nested set, generating slugs, then clearing the application cache and restarting PHP-FPM. Links to how to run all of these can be found on this page:
If running those does not resolve the issue, then we have a query that can help identify data corruption, which can sometimes happen when long-running processes (such as an import, move operation, etc) time out or are interrupted before completing as expected. See:
I would suggest running the sample query shown there to see if it turns up further information on the issue. Let us know what you find.
Additionally, if you're stuck, please show us what gets output if you run php symfony search:status.
Cheers,