Error when click on gridField column header

Hi,

I ahve a gridField setup like shown below: (just a excerpt of full interface code)

local!posiciones: a!forEach(
    local!posicionesBDI,
    {
      cod_descripcion: fv!item.cod_descripcion,
      estado: fv!item.des_estado,
      tecnologia: fv!item.des_tip_tinst,
      topologia: fv!item.des_conf_posicion,
      num_calle: fv!item.num_calle,
      juego_barras: fv!item.cod_matricula,
      afectada: if(
        a!isNullOrEmpty(ri!expCon),
        "-",
        if(
          contains(ri!expCon.codigo,tostring(fv!item.cod_descripcion)),
          "SI",
          "No"
        )
      )
    }
  ),
  a!gridField(
      label: if(isnull(ri!expCon),"Posiciones del parque afectado por el informe","Posiciones del parque afectado por el expediente"),
      data: local!posiciones,
      columns: {
        a!gridColumn(
          label: "Código",
          value: a!richTextDisplayField(
            value: a!richTextItem(
              text: fv!row.cod_descripcion,
              style: if(
                fv!row.afectada = "SI",
                "STRONG",
                "PLAIN"
              ),
              color: if(
                fv!row.afectada = "SI",
                "POSITIVE",
                "STANDARD"
              )
            )
          ),
          sortField: "cod_descripcion"
        )
      }
    )

Whenever I click on column header to get the grid ordered by this column, I get following error:

Interface Definition: Expression evaluation error [evaluation ID = f4e1f:68ae7] : An error occurred while executing a save: Expression evaluation error at function fn!error [line 120]: com.appiancorp.suiteapi.type.TypedValue cannot be cast to java.lang.Comparable

There is not save at all in my code, so I can't understand what error message is saying.

Any ideas of what I'm doing wrong?

I'm working with Appian cloud v23.2

Thank you all!