Verifying based on https://bugzilla.redhat.com/show_bug.cgi?id=1967320#c5
Just to clarify. This feature has been reverted as it requires the ability to modify cluster MTU at runtime.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (Moderate: OpenShift Container Platform 4.8.2 bug fix and security update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2021:2438