Most of the service-mesh tests are failing in 4.18, while passing in main (4.20).
It might be that are fixes in main that should be back-ported to 4.18.
My immediate suspect for back-porting is https://github.com/RedHatQE/openshift-virtualization-tests/pull/1581, but there are actually more service-mesh related PRs in main that were not back-ported, so each of them should be examined and decided whether to back-port it or not.