This issue happens when the listing site is set to adapts a specific setting of links. With the WP Job Manager plugin, it creates its own set of links that are permalinks on how it loads all listing pages. Therefore when the search page keeps on reloading this simply means you have set up your permalinks incorrectly.
This mostly happens when you have the permalinks set to plain rather than any other permalink settings.
Here is an exact replica of the issue:
To fix this you would have to use a different permalink option instead of the plain option. I would recommend setting your permalinks to pick the “postname” option asit is the most recommended WordPress format and also appears SEO friendly.
Here is the search option now working: