QuickSort Partition Condition

In the partition method for QuickSort provided below, what potential issue arises if the condition in the if statement is changed from arr[j] < pivot to arr[j] <= pivot?

public class SortUtil {
    public static int partition(int[] arr, int low, int high) {
        int pivot = arr[high];
        int i = low;
        for (int j = low; j < high; j++) {
            if (arr[j] < pivot) {
                int temp = arr[i];
                arr[i] = arr[j];
                arr[j] = temp;
                i++;
            }
        }
        int temp = arr[i];
        arr[i] = arr[high];
        arr[high] = temp;
        return i;
    }
}