If you want to completely rename a previously created job or clone an existing job and further edit it, you will need to change the job’s Meta title.
After you update the job’s Job title section, it will change the name of the job on your career site and inside the app.

It won’t update the name of the job's tab, after the candidate opens that job on your career site.

To update the name that appears in the job’s tab, while editing your job, scroll down to the Meta descriptions for SEO section and edit the job’s Meta title.

After you save the changes, it will be updated.