The search form doesn't show me all the results

Hi !

I don’t know why but the search doesn’t retrieve me all the results…

Here is the page that lists all the “trajets” (custom post type): https://www.leshautesardennes.be/covoiturage/liste-des-trajets/

If I type “Lierneux” in the first field of the search box, I have no results but normally there should be one … If I type “Vielsalm”, I have some results but not all of them…

I don’t understand why ??

https://www.ads-software.com/plugins/wp-custom-fields-search/