When searching for assets in my Art Library, I do not get results from marketplace purchases or subscription sets if I search for the name of the asset. For example, I have the PHB and XGE compendiums, but if I search for 'Dwarf,' I don't see any premium assets from the PHB or XGE (or from the Subscription sets). As an experiment, I right clicked one of the Drow tokens from the PHB premium asset list and chose to add it to My Library. That one Drow token shows up in a search for 'Drow' now, but the other PHB Drow tokens still do not.