Both port7 and port8 contain mac_address: "ec:0d:9a:8c:c6:96".
One of them (or both) needs to be changed so tests are not confused.
Not sure why currently only mlx5 test is failing, but two interfaces with the same MAC address is definitely a bug.

[0] https://s3-logs.fd.io/vex-yul-rot-jenkins-1/csit-vpp-perf-verify-2302-2n-clx/2/log.html.gz#s1-s1-s1-s1-s2-t1-k2-k9-k1-k1-k1-k21