Environment action:prepare does not set url in UI


I am using the environments for deployments and face the following issue.
when using the action: prepare for a job and also the url: the url is not set/changed in
the environment UI’s live environment button.
The url of environment ‘dev’ is set to www.test.org and I want to change it.
The job is:

   stage: whatever
       name: dev
       action: prepare
       url: www.moretests.org

when this job is run the url is the UI is not changed. Only if I don’t use the prepare action the url is changed.

Because in the gitlab documantiton example the url is set when using the prepare action, I was expectiong that the url would be changed.

Can someone confirm that it is expected behaviour that the url is not set in a job that has the action:prepares