Search box on records not searching one-to-many related records

Hi Appian Community,

I have a use case where I'm using a record type as the source for a readOnly grid.  This grid contains both record fields and related record fields, and I'd like for all fields of this grid to be searchable using the out of the box search functionality.  Per appian documentation at https://docs.appian.com/suite/help/23.2/filter-the-record-list.html:

When you hide search on the record list, the search box on the grid will use the default search behavior, searching across all fields referenced in the grid. The search box will also use the default placeholder text of "<Plural record type name>".

The above described functionality is what was desired, so I went ahead and hid search on the record type while setting the "showSearchBox" parameter on the readOnly grid to "true".  However, the result is that related records fields with a one-to-one relationship are still searchable, but related records with a one-to-many relationship cannot be searched.  Is this expected behavior?

Thanks in advance for any help!