SAP PO B2B not picking correct control Key for Plain to IDOC scenario

Hello,

I am building scenario (Plain to IDOC). Plain file will be copied on PO server and from there pick the file and use MM to transform into IDOC and hit in SAP S/4.

I created the message in B2B plain message editor with unique Key, imported the XSD into ESR and completed the rest of steps in ESR then in ID created the sender channel wilt File adapter (as file was place locally) and created IDOC_AAE receiver channel to load in S/4. whenever I am executing the sender channel, it is not picking the correct control key due to it is failing.

Please share your expert advice to solve it.