Limit in a lookup field and "More results" doesn't resolve any new items

Hi folks, I've had a lookup field for teaching faculty in use for several years.  This lookup field is rather large - 2800 items.  It has now stopped at the 1992nd record, and then you get to click on "More results", but it never resolves.

I was thinking about creating a calculated field called "Teaching faculty O-Z, so I was looking for help with the syntax.