Duplicate slugs for job listings with the same name

Hi,

I’m creating a recruitment site and keep coming across the same issue. Naturally the jobs that we list will sometimes have the same post name. For example, if we’re recruiting for multiple Developers in London we would have job listings for:

Full Time Developer in London – /full-time-developer-in-london

and

Full Time Developer in London – /full-time-developer-in-london-2

I want to find a way to append the Job ID to the permalink to avoid getting duplicate URLs and URLs that contain the -2

I’ve gone into Settings > Permalinks and changed the structure of job post types to be /%postname%-%post_id%/ but that just returns the following:

/full-time-developer-in-london-1234
/full-time-developer-in-london-2-5678
/full-time-developer-in-london-3-9876

How can I get the permalink structure setup so that I can have the same job name + job ID in the URL without getting the -2, -3 etc?

Thanks in advance!