In short, .NET is trying to prevent an endless loop that could occur. When a change to the Text property occurs, .NET will try to match that new value to the current items and change the index for you, thereby firing the SelectedIndexChanged event again.

People coming here looking for a VB implementation of Delegates can refer to the code below

```vb
'Declares a delegate sub that takes no parameters
Delegate Sub ComboDelegate()

'Loads form and controls
Private Sub LoadForm(sender As System.Object, e As System.EventArgs) _
	Handles MyBase.Load
	ComboBox1.Items.Add("This is okay")
	ComboBox1.Items.Add("This is NOT okay")
	ResetComboBox()
End Sub

'Handles Selected Index Changed Event for combo Box
Private Sub ComboBoxSelectionChanged(sender As System.Object, e As System.EventArgs) _
	Handles ComboBox1.SelectedIndexChanged
	'if option 2 selected, reset control back to original
	If ComboBox1.SelectedIndex = 1 Then
		BeginInvoke(New ComboDelegate(AddressOf ResetComboBox))
	End If

End Sub

'Exits out of ComboBox selection and displays prompt text 
Private Sub ResetComboBox()
	With ComboBox1
		.SelectedIndex = -1
		.Text = "Select an option"
		.Focus()
	End With
End Sub
```

**Further Reading**: See this post (mine) on [changing Combobox Text in the `SelectedIndexChanged` Event][1] which goes into a little more detail as to why you need to use a delegate as a workaround to change the ComboBox Text.  


[1]: https://codingeverything.blogspot.com/2013/02/handle-text-change-in-selected-index.html


Code example:

    private void comboBox_SelectedIndexChanged(object sender, EventArgs e)
    {
    	if(some condition)
    	{
    		comboBox.Text = "new string"
    	}
    }

My problem is that the comboBox text always shows the selected index's string value and not the new string. Is the a way round this?

How do I Change comboBox.Text inside a comboBox.SelectedIndexChanged event?

It's because you need to nest col calls inside of a `.row` class so they can properly clear the floats. 

Right after the combo boxes, the line `<div clas="row text-center"><div class="col-md-12>`" is getting overlayed on top of the other fields.  Either add them above it or add `style="clear:both"` to the row column.

[**Here's a working demo in fiddle**](https://jsfiddle.net/KyleMit/2Lmgwecy/)

I have a fairly complex Bootstrap 3 tabgroup of forms that are populated with combo boxes that work fine at desktop width, but in mobile the combo boxes are frozen or something and won't show the drop down.

Here is the first of the four forms embedded in the tab-group...

             <form role="form" id="prop-search"  name="prop-search" method="get" target="_blank" action="search.php">
                
                  <input type="hidden" name="searchtype" value="Residential">
                

                  
                  <div class="col-md-2 col-sm-6 col-xs-6">      
                    <div class="form-group">
                      <label for="location">City</label>
                      <select class="form-control" id="area" name="area">
                      
                        <?php
                          $action=basename(__FILE__, '.php');               // load action from filename for consistancy 
                          $controller = new retsController($action . '-cities'); // register controller with page action and parameter
                          $controller->invoke();                            // invokde controller to get view
                        ?>     

                      </select>
                    </div>
                  </div>
                  
                  <div class="col-md-2 col-sm-6 col-xs-6">
                    <div class="form-group">
                      <label for="type">Type</label>
                      <select class="form-control" id="proptype"  name="proptype">
                        <option selected>House</option>
                        <option>Condo</option>
                        <option>Townhome</option>                    
                      </select>
                    </div>
                  </div>
                    
                  <div class="col-md-2 col-sm-6 col-xs-6">
                    <div class="form-group">
                      <label for="bathroom">Baths</label>
                      <select class="form-control" id="baths" name="baths">
                        <option>1</option>
                        <option selected>2</option>
                        <option>3</option>
                        <option>4+</option>
                      </select>
                    </div>
                  </div>
                  <div class="col-md-2 col-sm-6 col-xs-6">
                    <div class="form-group">
                      <label for="bedroom">Beds</label>
                      <select class="form-control" id="beds" name="beds">
                        <option>1</option>
                        <option>2</option>
                        <option selected>3</option>
                        <option>4+</option>
                      </select>
                    </div>
                  </div>
                                           
                  <div class="col-md-2 col-sm-6 col-xs-6">
                    <div class="form-group">
                      <label for="minprice">$-Range</label>
                      <select class="form-control" id="pricerange" name="pricerange">
                        <option value="0-100">$0-$100k</option>
                        <option value="100-175">$100k-$175k</option>
                        <option value="175-250" selected>$175k-$250k</option>
                        <option value="250-325">$250k-$325k</option>
                        <option value="325-400">$325k-$400k</option>
                        <option value="400-500">$400k-$500k</option>
                        <option value="500-600">$500k-$600k</option>
                        <option value="600-750">$600k-$750k</option>
                        <option value="750-900">$750k-$900k</option>
                        <option value="900-1100">$900k-$1.1m</option>
                        <option value="1100-1500">$1.1m-$1.5m</option>
                        <option value="1500-100000">$1.5m+</option>              
                      </select>
                    </div>
                  </div>
                
                  
                  <div class="row text-center">
                    <div class="col-md-12">
                      <div class="form-group">     
                      
                        <input type="submit" name="submit" value="search" class="btn btn-default btn-block">  
                      </div>                     
                    </div>
                  </div>
             
                </form>

Here is a quick-n-dirty fiddle showing the problem.

https://jsfiddle.net/edkwudy9/

Notice that if you pull the width wide enough where you get the 6 columns (col-md-2 in Bootstrap), the dropdowns work just fine, but when you shrink the width to col-sm-6 col-xs-6, they stop working.

I just have no idea what could be wrong and I'm burning through unbillable hours with this issue like no ones business.  

I am a backend developer who got myself roped into this project and now find myself somewhat over my head with debugging BS3 and mobile.

the actual dev site to see the control in action...

http://webwarephpdevelopment.com:8080/index.php