Custom views on lookup wont work without name field
Quick tip here, when setting a custom view on a lookup in the form designer:
Always ensure that the name attribute is on the view too, even if it wont be displayed.
I had noticed that my search results were not working at all when I had typed in the lookup field. After an hour of troubleshooting, I added the name field onto the view and voila! Search and the control in general started behaving.