I uploaded an image my-image.jpg of dimension 1280x854, after that, I went to Dashboard > Media to crop it to 854x854. (Apply changes to All Image Sizes.)
This however only change its thumbnail in Media Library, when I click the thumbnail, the popup window shows still the original image, before cropped.
In the Uploads folder, I have checked that the cropped image files are existing, with name like my-image-e15249112352.jpg
I tried to get the image by its id:
The expected return is
but the actual return is
You are using 'large' size, and that is not the full image. For full image, you should use 'full' instead of 'large':
Large image is size based on the settings in the WordPress Settings Media.