ADUM3190S, EAOUT2 gains out of datasheet spec


We got a batch of your ADuM3190S parts specifically labeled ADUM3190AF-EMX and it seems that the output gain for EAOUT2 varies greater than the datasheet spec of 2.5 - 2.7 V/V.  I'm wondering if there's any known reason as to why this could be occurring?

Many Thanks,