When user navigates through keyboard using <tab> key in the header region, there is a ‘Toggle messaging drawer’ button, on activating opens a popup, navigate further inside the popup to ‘See all’ button, 'contacts' button, and 'messaging preferences' button. Observe that clear and outlined focus indictor is not provided for ‘See all’, 'contacts' button, and 'messaging preferences' button. It is just an underline.

Example below: