hashJoin - Multivalued field

[Kojo]

I am trying to solve one problem, exactly as the case described here:

http://lucene.472066.n3.nabble.com/Streaming-expression-API-innerJoin-on-multi-valued-field-td4353794.html

I cannot accomplish that on Solr 6.6, my streaming expression returns
nothing:


hashJoin(
  search(scholarship, zkHost="localhost:9983", q=*:*, fl="p_number",
sort="p_number asc"),
  hashed=cartesianProduct(
      search(articles, zkHost="localhost:9983", q=*:*, fq="processes:[1 TO
*]", fl="processes, id", sort="id asc"),
  processes,
  ),
  on="p_number=processes"
)

Both fields are of type string.


One strange thing is that if I filter the first query using fq, some
results appear.

hashJoin(
  search(scholarship, zkHost="localhost:9983", q=*:*, fl="p_number",
sort="p_number asc", fq= "sch_id:905 OR sch_id:3487"),
  hashed=cartesianProduct(
      search(articles, zkHost="localhost:9983", q=*:*, fq="processes:[1 TO
*]", fl="processes, id", sort="id asc"),
  processes,
  ),
  on="p_number=processes"
)



{
  "result-set": {
    "docs": [
      {
        "processes": "00/01011-6",
        "p_number": "00/01011-6",
        "id": "43256"
      },
      {
        "processes": "97/13133-4",
        "p_number": "97/13133-4",
        "id": "43256"
      },
      {
        "EOF": true,
        "RESPONSE_TIME": 343
      }
    ]
  }
}


Can you help me, please?