SetValue dependency file not working on basic text field

Hi,

Trying to get the SetValue dependency file working on a basic text field using a dependency file.

I have used successfully before on a decimal field but struggling here.

Below is an example of the dependency file I have placed into ...\custom\Extension\modules\Opportunities\Ext\Dependencies\<dependencyfile.php>

I expect when I create an Opportunity record, the value 'ABC' will appear in the text field, however it is just showing empty.

I tested the logic by putting the value in as a Calculated Field in Studio and that works. However, I need to use the Dependency file approach for my real life example as it is more complex than this basic test. In my real life example I also got it to work in Studio, but not working in the Dependency file.

Help will be much appreciated.

Thanks

Neil

<?php
/*
Set Default Values - Opportunities
*/


// test SetValue
$dependencies['Opportunities']['setvalue_dep_test'] = array(
'hooks' => array("edit", "view"),
'trigger' => 'true',
'onload' => true,
//Actions is a list of actions to fire when the trigger is true
'actions' => array(
array(
'name' => 'SetValue',
//The parameters passed in will depend on the action type set in 'name'
'params' => array(
'target' => 'symtest_text_c',
'value' => 'ABC',
),
),
),
);