Not retrieving the character at an index of a list correctly?

Question

I am writing a program that recursively iterates through a list, provided the index of the current character and a list of characters. However, when I run the following program:

(defun printAllElementsRecursively (index providedList)
    (if (>= index (length providedList))
        (return-from printAllElementsRecursively NIL)
    )
    (defvar currCharacter (nth index providedList))
    (print (format nil "Character at index ~a: ~a" index currCharacter))
    (printAllElementsRecursively (+ index 1) providedList)
)

(printAllElementsRecursively 0 '(A B B A))

I get the following output:

"Character at index 0: A" 
"Character at index 1: A" 
"Character at index 2: A" 
"Character at index 3: A" 

This seems strange, considering that the value of index does increment correctly.