is there a shortcut to force Android Studio to show the method signature? Then I firstly want to call a method I see it: <img src="https://i.stack.imgur.com/Tibzd.png" alt="enter image description here"> But then when I leave this and reenter the signature I dont see it anymore: <img src="https://i.stack.imgur.com/eRMtn.png" alt="enter image description here">

Is this really what you are talking about? This command name is "Parameter info". On Windows, it's assigned to <kbd>Ctrl</kbd>+<kbd>P</kbd> by default. On Mac, it's assigned to <kbd>Command</kbd>+<kbd>P</kbd> by default. You can change the keys as well from setting.