title: MongoDB $text search not returning expected results
body: <p>I created a text index based on <code>title</code> and <code>main_body</code> fields in my Mongo Collection. I have for instance an article with the title: "Abby Bengtsson" and her name "Abby", appearing throughout the actual article in <code>main_body</code>.</p>
  
  <p>Making a text search query: <code>{$text: {$search: 'abby bengtsson'}}</code>, returns the desired article, along with a couple more.
  <a href="https://i.stack.imgur.com/k3r71.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/k3r71.png" alt="enter image description here"></a></p>
  
  <p>But simply querying her first name: <code>{$text: {$search: 'abby'}}</code>, returns nothing.
  <a href="https://i.stack.imgur.com/wR11R.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/wR11R.png" alt="enter image description here"></a></p>
  
  <p>I have tried using Mongo Compass, Downloaded Studio 3T, and using ssh and terminal commands on the server directly. 
  <a href="https://i.stack.imgur.com/N700D.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/N700D.png" alt="enter image description here"></a></p>
  
  <p>But I don't understand why this happens.. The same goes for other key words in other articles.</p>
  
  <h2>JSON Doc example</h2>
  
  <pre><code>{
  "_id" : ObjectId("5e0f4ded35fbd16f21bf3655"), 
      "category" : {
          "category_id" : "5010", 
          "slug" : {
              "0010" : "profiler", 
              "0020" : "profiler", 
              "0030" : "profiler"
          }, 
          "label" : {
              "0010" : "Profiler", 
              "0020" : "Profiler", 
              "0030" : "Profiler"
          }, 
          "bg_color" : "#B12CA6", 
          "txt_color" : "#ffffff", 
          "main_category_id" : "5000"
      }, 
      "featured_image" : {
          "main" : "https://img.norrbom.com/article/5e0f4d5e35fbd16f21bf3653/78805a221a988e79ef3f42d7c5bfd418-1578061277668/abby.jpg", 
          "mobile" : "https://img.norrbom.com/article/5e0f4d5e35fbd16f21bf3653/78805a221a988e79ef3f42d7c5bfd418-1578061277668/abby.jpg", 
          "square" : "https://img.norrbom.com/article/5e0f4d5e35fbd16f21bf3653/78805a221a988e79ef3f42d7c5bfd418-1578061277668/abby.jpg"
      }, 
      "metadata" : {
          "title" : "Abby Bengtsson", 
          "description" : "Hon sprudlar av energi och glädje, vilket smittar av sig på hela redaktionen när hon kliver in hos En Sueco. Med sig har hon sin ursöta följeslagare pomeranianen Melwin", 
          "og" : {
              "title" : "Abby Bengtsson", 
              "description" : "Hon sprudlar av energi och glädje, vilket smittar av sig på hela redaktionen när hon kliver in hos En Sueco. Med sig har hon sin ursöta följeslagare pomeranianen Melwin", 
              "image" : "https://img.norrbom.com/article/5e0f4d5e35fbd16f21bf3653/78805a221a988e79ef3f42d7c5bfd418-1578061277668/abby.jpg", 
              "type" : "article", 
              "site_name" : "En Sueco", 
              "url" : "https://www.ensueco.com/profil-abby-bengtsson"
          }, 
          "twitter" : {
              "title" : "Abby Bengtsson", 
              "description" : "Hon sprudlar av energi och glädje, vilket smittar av sig på hela redaktionen när hon kliver in hos En Sueco. Med sig har hon sin ursöta följeslagare pomeranianen Melwin", 
              "card" : "summary", 
              "image" : "https://img.norrbom.com/article/5e0f4d5e35fbd16f21bf3653/78805a221a988e79ef3f42d7c5bfd418-1578061277668/abby.jpg"
          }
      }, 
      "tags" : [
  
      ], 
      "title" : "Abby Bengtsson", 
      "state" : NumberInt(1), 
      "created" : ISODate("2020-01-01T04:17:00.000+0000"), 
      "modified" : ISODate("2020-01-01T08:27:54.000+0000"), 
      "version" : NumberInt(19), 
      "featured" : false, 
      "language" : "sv", 
      "magazines" : [
  
      ], 
      "slug" : "profil-abby-bengtsson", 
      "published" : ISODate("2020-01-02T10:14:00.000+0000"), 
      "published_until" : null, 
      "author_alias" : "Text: Sara Laine, sara@norrbom.com Foto: Mugge Fischer, mugge@norrbom.com", 
      "main_body" : "... stringified JSON object with article ...", 
      "article_id" : ObjectId("5e0f4d5e35fbd16f21bf3653"), 
      "origin" : "cms", 
      "site" : "0020", 
      "__v" : NumberInt(0)
  }
  </code></pre>
  
  <h1>EDIT 18-01-2020</h1>
  
  <p>I just tested something. It seems, that this issue only occurs for documents where the <code>language</code> property is set to <code>sv</code> (Swedish as per <a href="https://docs.mongodb.com/manual/reference/text-search-languages/#text-search-languages" rel="nofollow noreferrer">MongoDB Language Documentation</a>). If I change the value to <code>da</code> (Danish), the document is being returned, when I search for "Abby".</p>
  
  <p>I have currently solved my issue in production, by setting <code>language_overwrite</code> to a dummy field that doesn't exist.. Now all fields are being returned as they should. But the thing with the swedish language field still confuses me, as it is ONLY when I se the field to "sv" - and what sense does it make to have multiple language documents, and a text index that supposedly should return and search based on locale, if it doesn't work for one particular language variable?</p>