Doc ID 2758388.1 - Refer to this document
FA: SCM: OM: FBDI Order Import for Sales Order with Extensible Flex Fields are Not getting Reported in ESS Failure. (Doc ID 2758388.1)
How are other customers dealing with this bug after 21A upgrade?
Why would Oracle break something that was working earlier and now there is no workaround unless Oracle has to fix this bug.