Issues with Date data type

This is a known issue with 3 letters month names for international dates for few cultures. While 3 letters month names work well with English language, it breaks for few including Spanish. Hence, these 3 letters of month names need to be converted to full month names, then your conversion will work fine.

See the working here - Open a blank query - Home - Advanced Editor - Remove everything from there and paste the below code to test.

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjbUdfF01jUyVIrViVYyNNJ19XPVNTIC89AIVEl8PCNDFJ4Jbp6xIW4e0MzUvNSifLDjYgE=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [FECHA = _t]),
    #"Added Custom" = Table.AddColumn(Source, "Custom", each Date.FromText(try Text.ReplaceRange([FECHA],3,3,{"ENERO", "FEBRERO", "MARZO", "ABRIL", "MAYO", "JUNIO", "JULIO", "AGOSTO", "SEPTIEMBRE", "OCTUBRE", "NOVIEMBRE", "DICIEMBRE"}{List.PositionOf({"ENE", "FEB", "MAR", "ABR", "MAY", "JUN", "JUL", "AGO", "SEP", "OCT", "NOV", "DIC"},Text.Range([FECHA],3,3))}) otherwise "1-ENERO-1900",[Culture="es-ES"]), type date)
in
    #"Added Custom"