Thanks for your inquiry. We have tested the scenario and have managed to reproduce the same issue at our side. For the sake of correction, we have logged this problem in our issue tracking system as WORDSNET-14677. You will be notified via this forum thread once this issue is resolved.
Our product team has completed the analysis of your issue and the root cause has been identified. You are facing this issue because Aspose.Words does not support MS Word 2016 fully. We already logged this feature as WORDSNET-12458 in our issue tracking system. You will be notified via this forum thread once this feature is available.