Hyperledger fabric. If I send a transaction 10 times, the 9 is error and responds once in API server

I set up API, comm, MQ, Node server using centOS7 and provisioned hyperledger fabric on docker and upload my chaincode to node server. All of transactions(invoke, query) work well in node server(using cli command in a peer). But if I send transactions to API server, commonly 90% of transactions respond an error message and it responds correctly once in a while. Could you guess where this problem caused in my API server system?

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Source: StackOverflow