We recently ran into an issue where global search results for one of the entities wasn’t showing any data in the fields, for a system upgraded from CRM 2011 to Dynamics 365. The version of Dynamics 365 we used was 126.96.36.1999.
Upon digging further into this issue, I figured out that no column was selected as find columns in Quick Find view of the affected entity. In this instance it is Contact entity. This is somewhat strange because if we don’t select at least one column in the find columns, Dynamics 365 prevents us from saving the Quick Find view. How this happened is still unknown.
However, the fix to this issue was selecting at least one column in the find columns of Quick Find view. Once the change was saved and published I used the Global Search using same query. This time the resulting records for Contact entity had data in the fields.