The most common cause for job listings not showing up is a javascript error, since jobs are loaded via ajax.
To check for Javascript errors:
- Go to your jobs page
- (in Chrome browser, but others are similar) Right click the page and click inspect.
- Go to the console tab and view the errors
If there is a javascript error you need to work out which plugin (or theme) is causing it and fix it (or disable the plugin).
If you are unsure you can disable everything and enable 1 item at a time until the error occurs.