I'm not aware of such limitation.
Can you try with the same device but using a copper port?
My feeling is that you either have some sort of configuration issue or you might have hit a software defect.
In case MRVP works on copper ports using the same configuration, then you should head to opening a JTAC case.
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If this worked for you please flag my post as an "Accepted Solution" so others can benefit. A kudo would be cool if you think I earned it.