Keyboard navigation of Endnote library not working for Author field

I have always navigated through my Endnote library to find a particular entry by sorting by Author (typically) and then typing the first letter or few letters of the name, and it takes me right there. This has always worked for the other fields (once sorted), as well. It recently stopped working for the Author field for me (I get an audible ding when I try), in X7 and now X8 (recently upgraded), though it still works for the other fields. Any suggestions? I am running X8 in Windows 7, though I started having this problem a week or two ago in X7.

Back in 2015, someone was having trouble with sorting and recovering their library fixed the problem.