Observation Details
When opening a dialog window:
The non-interactive contents of the dialog window are not accessible via keyboard.
Dialog window "Alle Geräte ansehen" can be opened and closed by keyboard but contents cannot be scrolled by keyboard.
Remediation Notes
Opening a dialog window by keyboard navigation must set the focus to the dialog window's content. Opening a dialog window must trap keyboard focus inside the dialog window, so underlying content cannot be accessed while dialog window is opened. Closing the dialog window, focus must be set to the triggering element again.
Ideally, the first focusable element in a dialog window can be used to close the dialog window, so opening and closing of a dialog window can be done without the need of navigating through other focusable elements. Although simple dialog windows, e.g. asking for confirmation, and providing "Accept" and "Cancel" buttons, might not have an explicit "Close" button and may set focus to the dialog window's "main purpose action" instead.
The non-interactive content of the dialog window, when overflowing, must be accessible via scrolling by keyboard navigation (ARROW UP / DOWN).