WordPress adding 12 images for each image uploaded

When I upload an image to WordPress it adds 12 images to the /wp-content/uploads/.. folder.
In the media settings I have :
-Crop thumbnail to exact dimensions is UNCHECKED
Thumbnail size 150 x 150
Medium size 300 x 300
Large size 500 x500

I uploaded an image with dimensions of 863 px by 1150 px
Wordpress created:
Image 1: 863 x 1150
Image 2: 100 x 133
Image 3: 112 x 150
Image 4: 225 x 300
Image 5: 375 x 500
Image 6: 846 x 473 (bottom 2/3 of image cropped off)
Image 7: 846 x 1127
Image 8: 862 x 482 (bottom 2/3 of image cropped off)
Image 9: 862 x 1148
Image 10: 863 x 483 (bottom 2/3 of image cropped off)
Image 11: 863 x 662 (bottom 1/2 of image cropped off)
Image 12: 863 x 671 (bottom 1/2 of image cropped off)

This makes no sense to me, can you help explain please?

thank you