Google has announced that it now supports site names for subdomains on mobile devices. Site names are the title and name of the site that appears in the search results listings. Google has updated its help documentation to specify subdomains on mobile. The rollout of site names began in October 2022 with support for English, French, German, and Japanese, and now includes support for subdomains on mobile devices for the same languages. The new feature is supported by Google search ads on desktop, meaning that the site name, favicons, and ad label will be more prominent in mobile search.

source: Google Site names now support subdomains on mobile devices