Replace Operation Cosmos Db

nitinrahim you will definitely get a response if your request is reaching to database, Azure Cosmos DB is designed to have very high concurrency, it does billions of concurrent transactions. Basis your explanation it may be that during high concurrency the client app getting challenges, please refer https://learn.microsoft.com/en-us/azure/cosmos-db/nosql/performance-tips-java-sdk-v4?tabs=api-async to follow best practices from client side. If it doesn't solve the issue then I will recommend you to raise a support ticket.