[temeritatis]

> There are a few basic features missing, such as that if I search for something I wrote in the notes of password, that the client shows the according password

It might be that your search term is a partial of a word. This is fine when searching some fields, but for finding entries with that word in the notes section, the search term needs wildcards. You can read more about it here: https://bitwarden.com/help/searching-vault/

But to paraphrase: "notes: Item's notes. Only full-word matches will be listed unless you use wildcards."

Hope it helps.