@beta
Which version of Metabase? Which datasource?
What type is the column? Settings > Admin > Data Model > (database) > (table) > (column)
v0.31.2 (Latest)
My data source
The type of column is empty
@beta
You need to define the Field Type for Field Filters to function.
https://www.metabase.com/docs/latest/administration-guide/03-metadata-editing.html