404 Error not possible to fix with permalink structure

Using WP Pro Real Estate 6.
Since a few days, we receive the updates from our listing just like always, meaning the data arrives on our website. But the links of all the listings lead to a 404-page. I changed the permalink structure back and worth with no effect. Website: http://www.villanoble.com/
Any problem solving suggestions?
Thank you in advance.

https://wordpress.org/plugins/contempo-real-estate-custom-posts/