Page not displaying results

Hi,

I have installed this plugin on my multisite network, however my subsites do not show the actual search result page. Also, is it even possible to use this plugin with subsites? I set it up according to https://www.wpbeginner.com/wp-tutorials/how-to-add-google-search-in-a-wordpress-site/

Here is my example:

https://wordpress.societe-rmd.com/ (displays search result page but results are only for this site)

https://wordpress.societe-rmd.com/site-drac/ (Does not display search result page (Search Page Rarget URL = https://wordpress.societe-rmd.com/site-drac/?page_id=))

https://wordpress.societe-rmd.com/site-fms/ (Does not display search result page(Search Page Rarget URL = https://wordpress.societe-rmd.com/site-fms/?page_id=))