Update Activity Status

I have a automation workflow that's not working and wondering what I have set up incorrectly.

🤔 This is the part that's not working - the activity isn't being marked as done.

Would appreciate any help! I've only tested this once so if there's nothing wrong with my workflow, I can re-test it. I need to replicate this throughout my process so want to make sure I get this correct before moving on.

Thank you!