Solr EDisMax issue

Question

I'm trying to get some documents from the index, with no luck.

I have a document like this

<str name="id">4</str>
<arr name="title">
<str>whatever thing</str>
</arr>

If you notice, the title says "thing". This field type is "text_es", described just as follows:

<fieldType name="text_es" class="solr.TextField" positionIncrementGap="100">
    <analyzer> 
        <tokenizer class="solr.StandardTokenizerFactory"/>
        <filter class="solr.LowerCaseFilterFactory"/>
        <filter class="solr.StopFilterFactory" ignoreCase="true" words="lang/stopwords_es.txt" format="snowball" enablePositionIncrements="true"/>
        <filter class="solr.SpanishLightStemFilterFactory"/>
        <!-- more aggressive: <filter class="solr.SnowballPorterFilterFactory" language="Spanish"/> -->
    </analyzer>
</fieldType>

If I do the following search:

http://localhost:8983/solr/select/?q=thing&defType=edismax&qf=title^20.0+text^0.3

It returns nothing. It works on Solr 3.6, but doesn't work on Solr 5.2. I'm consuming everything using Solarium (PHP), but not sure how to fix this.

What I'm doing wrong?

Thanks in advance!