401 from API when trying to update record from integromat

So I’ve got most of an email validation sequence set up using custom actions and Integromat.

The last step, a PUT request to update records isn’t working, it’s returning a 401 (see image below)

The step immediately before successfully sends a GET request which is working well. I’ve even tried starting by cloning it just to make sure the auth isn’t the problem.

Any ideas why suddenly the auth isn’t working?

(btw the variable at the end of the URL in the screenshot is the record id)