reordered and duplicated packets when using UDP over loopback interface

We are seeing UDP packets being reordered and duplicated when being sent over lo. We can see this because we're sending MPEG transport streams, which have their own sequence number in their headers, though it can also be seen by sending the traffic as RTP and seeing packets come in reordered that way. This may be potentially related to this question, though we are not doing large writes, as we're using code that sends data over networks, so our packets fit in 1500 byte frames. We've tried configuring RFS with the default suggested configurations (our lo has only one rx-queue), but this doesn't seem to make a difference. This seems to occur regardless of application, whether its our own UDP/RTP code or an application like srt-live-transmit (we didn't test FFMPEG but it probably behaves similarly). This is on Redhat 8.3 (kernel 4.18.0-240.15.1.el8_3).