And I do have to agree with Tudor above, the fact that LAG worked on the hub 4 previously was always, always an unsupported 'feature', which probably worked more by accident than design; on that basis if a subsequent update broke it, well then, unfortunately sorry about that, but fair enough really.
VM are absolutely not going to roll the firmware back, I'm afraid that ship has sailed, neither are they going to spend money on engineering time to reinstate this feature.
So the question here is 'what are you going to do about it?