One of the features of DA is to see the search results prior to accepting a search. This is accomplished through the Results tag at the bottom of the Search Details pane at the bottom of the Search tab within a Case. Prior to upgrading to DA 12.5.0, hit highlighting was provided in order to help fine tune the search criteria and re-run the search prior to accepting its results. After upgrading DA to the 12.5.0 release, this hit highlighting no longer occurs.
Workaround:
Create a Research Folder in which to run the search and accept the results to see the hit highlighting in the Review tab, then delete the Research Folder when the criteria has been determined and used within a Case.
This issue has been resolved in the following release:
Enterprise Vault 12.5.2
https://www.veritas.com/support/en_US/downloads/update.UPD334575