QuickSort Partition With Duplicate Values

Consider the following partition method, which is used in a QuickSort algorithm. What potential issue arises when the array to be partitioned contains elements equal to the pivot value?

public class QuickSortPartition {
    public static int partition(int[] arr, int low, int high) {
         int pivot = arr[high];
         int i = low;
         int j = high - 1;
         while(i < j) {
             while(arr[i] < pivot) {
                 i++;
             }
             while(arr[j] > pivot) {
                 j--;
             }
             if(i < j) {
                int temp = arr[i];
                arr[i] = arr[j];
                arr[j] = temp;
             }
         }
         int temp = arr[i];
         arr[i] = arr[high];
         arr[high] = temp;
         return i;
    }
    
    public static void main(String[] args) {
         int[] numbers = {3, 9, 4, 8, 5, 7, 6};
         int pos = partition(numbers, 0, numbers.length - 1);
         System.out.println("Pivot position: " + pos);
         System.out.println(java.util.Arrays.toString(numbers));
    }
}