I had an interestng query from a business user who could not his name from the “Created By” custom filter. The custom filter is set to display author.
The Created By uses the author from the office document rather the author shown in SharePoint library.
There is a maximum of 50 values per custom filter Manage filters
Alternative is to use the KQL using the search property or focused the query to limit the results returned. , e.g.
DisplayAuthor: