Hello Rebekka,

i am assuming you are talking about my tasks and all tasks menu as there is no bydefault search for the project menu in odoo v17, 

thus you need to take help of someone technical for this work and ask them to inherit the action on which the menu is getting called and then remove the bydefault search on that.

if you're asking for help in some other version or do have some other query reply below my response.

Thanks