Update Rule [CDO] campaign step

I have a very basic issue (I think) with creating a Campaign step using "Update Rules" that should update the value of a specific field in a CDO.

I have a Segment based on a CDO. I created an Update Rule under Data Tools > Update Rules, but I cannot see my Rule in the dropdown list when adding the Update Rules step in the Campaign :(

It looks like Campaigns do not allow me to select Update Rules that are based on changes to CDO records.

In this case, do you know a simple way to add a step in Campaign canvas after sending an email that would allow me to update a field value for a specific CDO record for linked Email Address?