Sorry, based on the google translation of your problem, I am not sure what is wrong with the Search window for you. For me, on Windows 10, the search engine works just fine on Notepad++ v8.1.4.

It should be noted that Notepad++ is a Windows application, and the developers only support Windows environments; if you can make it work in Wine (which is what PlayOnLinux uses under the hood), great for you! But that’s not a supported use case.