Receiver reports double data rate at times

# Context

* Version of iperf3: iperf 3.17.1 (cJSON 1.7.15)

* Hardware: Intel(R) Xeon(R) Gold 6354 CPU @ 3.00GHz (20 vcores)
* 56 GB memory

* Operating system (and distribution, if any): Oracle Linux Server release 8.10 64 bit

_Please note: iperf3 is supported on Linux, FreeBSD, and macOS.
Support may be provided on a best-effort basis to other UNIX-like
platforms. We cannot provide support for building and/or running
iperf3 on Windows, iOS, or Android._

* Other relevant information (for example, non-default compilers,
libraries, cross-compiling, etc.):
CPU affinity setting, IPv6 flow label, SCTP, TCP congestion algorithm setting, sendfile / zerocopy, socket pacing, authentication, bind to device, support IPv4 don't fragment, POSIX threads

Sender is on a VM in OCI using "Optimized" shape with SR-IOV interfaces.

_Please fill out one of the "Bug Report" or "Enhancement Request"
sections, as appropriate. Note that submissions of bug fixes, new
features, etc. should be done as a pull request at
https://github.com/esnet/iperf/pulls_

# Bug Report

* Expected Behavior
Sender and receiver report received speed correctly.

* Actual Behavior
Intermittently, receiver reports back double data rate on some streams (when using parallel streams).

* Steps to Reproduce
Run forward test with 50 Mbps with -P 10 and UDP
Also occurs without -P option

```
[ 5] local 10.218.11.55 port 56570 connected to 10.211.95.1 port 5201
[ ID] Interval Transfer Bitrate Total Datagrams
[ 5] 0.00-1.00 sec 5.96 MBytes 50.0 Mbits/sec 39028
[ 5] 1.00-2.00 sec 5.96 MBytes 50.0 Mbits/sec 39063
[ 5] 2.00-3.00 sec 5.96 MBytes 50.0 Mbits/sec 39062
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Jitter Lost/Total Datagrams
[ 5] 0.00-3.00 sec 17.9 MBytes 50.0 Mbits/sec 0.000 ms 0/117153 (0%) sender
[ 5] 0.00-3.01 sec 35.8 MBytes 99.7 Mbits/sec 0.008 ms 0/117153 (0%) receiver
```

* Possible Solution
Repeat a few times and problem may go away. Sometimes this only affects a few UDP parallel streams, but other times it affects all. Sometimes this issue does not happen.

Interesting to note that the total packets received correlate correctly.