gistfile1.txt

############# CODE IN TABLE ############# 
<skootable showconditions="true" showsavecancel="false" searchmethod="server" searchbox="false" showexportbuttons="false" pagesize="10" createrecords="true" model="PurchaseOrderItems" uniqueid="CustomFieldEditor" buttonposition="" mode="edit">
 <fields>
    <field id="Quantity_Purchased__c" decimalplaces="" valuehalign="" type=""/>
    <field id="Inventory_Key__c" valuehalign="" type="">
       <label>Inventory Code</label>
    </field>
    <field id="Price_Each__c"/>
 </fields>
 <rowactions>
    <action type="delete">
       <drawer title="Drawer Area" width="800" closehandle="true">
          <components/>
       </drawer>
    </action>
 </rowactions>
 <massactions usefirstitemasdefault="true"/>
 <views>
    <view type="standard"/>
 </views>
 <searchfields/>
 <actions defaultlabel="Global Actions" defaulticon="sk-icon-magic" usefirstitemasdefault="true"/>
</skootable>


############# JAVASCRIPT CODE ############# 
(function(skuid){
    var $ = skuid.$;
    
    $(function(){
        $('#CustomFieldEditor').find('input.ui-autocomplete-input').on('focusout', function(){
   
            console.log('test');
   
        });
    });
})(skuid);

I would imagine that "find('input.ui-autocomplete-input')" may be returning more than one element. You can try to loop through all of the found elements and add a listener to each one:

$('#CustomFieldEditor').find('input.ui-autocomplete-input').each(function(i, elem){
$(elem).on('focusout', function(){
console.log('test');
});
});