Hello NV,
In the signature tab, on the target side, instead of using BAPI RFC messages, kindly use Message1 and Message2.
Reason being, if you use BAPI RFC messages on the target side (which has occurrences of unbounded), then it causes multiplicity of service interface at Interface Determination level, and hence multiplicity of message (200 in your case for ex.).
Also, please maintain ignoreRecordsetName as true. I was wrong when I had suggested it as false.
Regards,
Souvik