I made a dropdown custom field called "Status" and I want to post a comment every time the custom field changes so that it's more specific about what the status was changed from and by who. I have the automation on Butler set like this:
which works as expected when the the status changes from a set value to another. However, when it goes from blank to a set value, it produces a comment that looks like this:

What steps do I need to take to make it so that when the dropdown custom field goes from being blank to having a value, the {customfieldvaluebefore} variable defaults to something like None or N/A? Is that possible? Does Butler support triggers based on when a custom field changes from something to another with dropdowns?