Getting right a query with date grater than now()

[stefanorumi7]

I have the following query that is returning nothing, but according to the data, it should.

final query = Query(
      where: [
        Where('columnA', value: valueA),
        WherePhrase([
          const Or('dateColumn').isExactly(null),
          const Or(
            'dateColumn',
          ).isGreaterThan(DateTime.now().toUtc().toIso8601String()),
        ]),
      ],
      limit: 1,
    );

What am I doing wrong?