Issue : Dataverse search is not working on regarding field of activity tables

Troubleshooting:

With regarding field of activity tables we are unable to fetch the records from global search.

Tested the same in vanilla and we see the same behaviour.

Enabled all Activities (EMAIL/TASKS/PHONE CALL/APPOINTMENT etc..) for dataverse search. But still with regarding field we cannot search the activities.

Ask : Is there any possible ways to search with regarding field of activity tables ?