I have a ootb n:n relationship between a table called FOI Tracker and a table called FOI - Exemptions. My main form for FOI Tracker contains a subgrid of related FOI - Exemptions, so that the user can select relevant Exemptions for that record.
I'm having trouble with the search functionality in the Lookup View of the FOI - Exemptions table. Ideally I'd like the search function to do a full text search of two columns - 'Name' and 'Exemption Number'. I have added these two columns to the Find by section of the Lookup View:

However, when I use the view, search will work for the start of the Exemption Number string, e.g.

But I cannot search by a substring of the Exemption Number, or any part of the Name column, e.g.


What's more, pressing Enter to browse all records returns nothing:

Have I configured this incorrectly? Is what I am trying to achieve possible?
Thank you!