Hi Bharani,
Please perform following checks:
1. Check whether your Idoc as well as Inbound FM related code changes correctly deployed to Production.
2. If no issue identified from code end in SAP then check the sender end(PI) the Idoc field mapping is correct.
3. I will not suggest to reprocess Idoc using WE19 in Production but you can test Idoc in Preproduction.
Regards,
Sudeesh Soni