공식 댓글
You have the Pro plan which allows you to process 3 gigapixels worth of imagery at a time for free. With a 20 megapixel camera that is enough to upload 150 images. If you used the downscaling factor of .25 you could upload as much as 600 images. You have 132 points in your account which is enough for you to upload an additional .66 gigapixels worth of imagery.
You purchased points previously which allowed you to process more imagery at a time. As you used the points, the number of images you can select has gone down since you have less points.
This has nothing to do with the file upload limit on your account which now is 2700 images.