The reason I asked is this: The WiiM Home App on its own doesn't fetch this kind of artist information, so it must come from one of the services you've subscribed to and which integrate with it through an API.
Possibly Qobuz or Roon?
Depending on what feAtures this API offers, WiiM might or might not have full control over the rendering of the output. If it comes e.g. as preformatted HTML and no documented functions for applying a custom style sheet, then they are mostly out of luck.
I think you should really file a ticket (tab "More..." => "Feedback and Ticket") to have the dev team really look into this. Ideally, send your feedback right after performing such a search. The logs send along with your ticket might make it easier to reproduce this exact behaviour.