title: RemoteAttribute not behaving as expected with null/empty data
body: <p>I want to validate user input using the [Remote] attribute.
  This is how this code looks in the model:</p>
  <pre><code>    [Remote(action:&quot;VertifyPeriod&quot;,controller:&quot;AllTasks&quot;)]
      public string Period { get; set; }
  </code></pre>
  <p>This is what the controller code looks like:</p>
  <pre><code>    [AcceptVerbs(&quot;GET&quot;, &quot;POST&quot;)]
      public IActionResult VertifyPeriod(AllTask allTask)
      {            
          if (!string.IsNullOrEmpty(allTask.Period))
          {
                  return Json(true);
          }
          return Json($&quot;Wrong period value!&quot;);
          
      }
  </code></pre>
  <p>View code:</p>
  <pre><code>        &lt;form asp-antiforgery=&quot;true&quot; asp-action=&quot;Create&quot;&gt;
          &lt;div asp-validation-summary=&quot;ModelOnly&quot; class=&quot;text-danger&quot;&gt;&lt;/div&gt;
          &lt;div class=&quot;form-group&quot;&gt;
              &lt;label asp-for=&quot;Period&quot; class=&quot;control-label&quot;&gt;&lt;/label&gt;
              &lt;input type=&quot;text&quot; asp-for=&quot;Period&quot; class=&quot;form-control&quot; /&gt;
              &lt;span asp-validation-for=&quot;Period&quot; class=&quot;text-danger&quot;&gt;&lt;/span&gt;
          &lt;/div&gt;
  </code></pre>
  <p>If the user leaves the string empty the condition returns true, although it should return false
  It is listed as null in the database.
  I noticed peculiarity: If set a breakpoint on a conditional statement, it will never be reached.
  If I make another check condition, not related to checking for null then everything works fine.
  IsNullOrWhiteSpace doesn't work either.
  What could be the problem?</p>