why we can not update a word document property from "SharePoint Properties"

I have a SharePoint online document library , which contains custom content type and 2 custom columns as follow:-

ChoiceOnly of type choice
TermOnly of type managed metadata linked to a term set

now i synced the documents inside my laptop using OneDrive application, and i can access those 2 columns as follow from word desktop app:-

now when i made the changes and i save the document, only the choice field selection will be saved to SharePoint, which the managed metadata value will be ignored, here is the document inside SharePoint:-

so is there a way to fix this? 

Thanks