Have you ever seen this prob in indexing ?

Hello,

Something is weird with a new website aged one month ago.
the website is indexed and very well.
last days, if do the search: site:domain.com i don't find the domain.com rooted only domain.com/pages etc...
BUT, if i do: "domain.com" i got the search the rooted domain.

PS: domain.com url is indexed in Google Search Console.

did anyone got this kind of problem ?