Actions button is not working properly

[Julienec]

I need your help. I have a 'Cancel' button that is enabled whenever the Request Status is 'Pending.' When the 'Cancel' button is clicked, the Request Status should change to 'Cancelled.' However, after clicking the 'Cancel' button, the status correctly updates to 'Cancelled' but then reverts back to 'Pending' after a few seconds. 

Actions config:

Actions' Only if this condition is true : AND(ISBLANK([action]), [Request Status] = "Pending")

[action] is the placeholder for generated file. so this formula says that is the [action] is null and [request status] is still pending