Hey Anand,
Without an error log, there can be many simple possibilities that get overlooked:
1. Check for the user authorization that processes the IDOC. Immediately after the process run transaction SU53 for authorization check.
2. Try to execute the IDOC manually in background mode for any errors. Maybe you need to handle background mode.
3. Force an error record to verify, if the system behaves the same in manual as well as auto mode.
If you have any additional details, please share for better inputs.
Regards,
Pranav.
