Document labels disappear in list view when search terms are matched in document title. For example, when viewing search results in the column view, the first image below shows the selected (Li-2014…) and two following documents with the appropriate pink label. The next image shows the same documents in list view and only one of the three document is correctly labeled (Monfreda-2008…). The only difference is the Li-2014… and Bradford-2005… documents have titles with words matching the search terms. As a consequence, discerning whether a document has been given a particular label depends on which viewing preference has been selected when viewing search results.
This is currently intentional to make the highlighting more obvious (and to reduce the noise). Possible workarounds are to either enable the “Labels” column or to use a different label style.
This behavior seems a bit inconsistent but I guess I understand the point from your perspective. Thanks for the alternatives.