It looks like the Office 365 Read Range activity uses a custom DataTable type with extra meta data, and simply providing the column name as text is not enough.
Instead, one must use the meta data of the DT variable produced by this activity and point the Filter Data Table activity to the correct column within this meta data. And then it works
EDIT
Actually, this is clearly a bug. It works with just the column name if you use the expression editor to insert it, rather than typing it directly: