See org.hibernate.search.query.dsl.impl.DiscreteFacetRequest.SimpleFacet.getFacetQuery():

		@Override
		public Query getFacetQuery() {
			return new TermQuery( new Term( getFieldName(), getValue() ) );
		}

Keep in mind that getFieldName() is supposed to return the facet name, and that the facet field is not indexed, only doc values are stored... Which means such a query will never work if:

• The facet field has a different name than the source field (@Facet.name has been set to something other than the source field name)
• or the source field is numeric (you would need a numeric range query instead of a term query in that case, see org.hibernate.search.bridge.util.impl.NumericFieldUtils.createExactMatchQuery(String, Object))

I think there is a few confusions in the code between the facet name (@Facet.name) and the source field name (@Field.name, @Facet.forField), and these confusions should be addressed.