Oracle datapump import error - AWS RDS for Oracle SE2 with S3 integration

Hi, I am trying to import the Oracle data dump file using S3 integration. We received the Dump file via SFTP from other customer and I could successfully copy it to DATA_PUMP_DIR, but when I try to import it using DBMS_DATAPUMP operation, I am getting the below error saying ORA-31694 : XXXX table "DBNAME.SYS_IMPORT_SCHEMA_02" failed to load/unload, ORA-02369: internal number in header in file <**.dmp> is not valid. did anyone face this issue before? if yes, can you plz provide some insights? I want to rule out RDS side of issues before asking the customer to check the file on their side