I fonud the answer here:
https://gist.github.com/iftee/73cbd9f080c5c7a943cff5e806997f90?permalink_comment_id=3314876#gistcomment-3314876
I added:
unset( $sizes['1536x1536'] );
unset( $sizes['2048x2048'] );
remove_image_size( '1536x1536' );
remove_image_size( '2048x2048' );
This removes the two big image sizes, but the -scaled image size is still there
I found out this:
When a new image is uploaded, WordPress will detect if it is a “big” image by checking if its height or its width is above a big_image threshold. The default threshold value is 2560px, filterable with the new big_image_size_threshold filter. If an image height or width is above this threshold, it will be scaled down, with the threshold being used as max-height and max-width value. The scaled-down image will be used as the largest available size. In this case, the original image file is stored in the uploads directory and its name is stored in another array key in the image meta array: original_image. To be able to always get the path to an originally uploaded image a new function wp_get_original_image_path() was introduced.
source:
https://make.wordpress.org/core/2019/10/09/introducing-handling-of-big-images-in-wordpress-5-3/
To remove it:
add_filter( 'big_image_size_threshold', '__return_false' );