Kerning is different than tracking. It only changes the spacing between a pair of characters. You do this by placing a cursor between the two characters.
Tracking affects the overall spacing for a range of characters. You make a selection of characters.
What you're seeing indicates you have selected a range of characters.
Thanks so much, Steve. I was selecting the letters rather than placing the cursor between them. I'll chalk it up to Monday! Appreciate your quick response.