@lakshmi , Thanks for posting this question.
Based on my understanding of your description, if you haven’t done this already so, kindly check if it’s due to firewall config. Kindly configure an inbound rule for the IP address of your search service and the IP address range of AzureCognitiveSearch
service tag.
/Azure Storage #grant-access-from-an-internet-ip-range
Ref: Indexer troubleshooting guidance for Azure AI Search #firewall-rules - IP address range restrictions only work if your search service and your storage account are in different regions. Kindly let us know, I'll follow-up with you further.