All my images get binarized when creating a version

I want to work on a dataset for tumor detection on mammograms in png format. When I create a version of my dataset, without applying any preprocessing, all the images are binarised, I don’t know why. Moreover, the binarisation is done at a very high threshold (the images become almost completely white).

Does anyone know how to fix this problem?

here is a screenshot of my dataset after generating a version :

What is the original upload format for the images?

As in, are they jpeg, png, or another format?

Hello, they are in a png format, but the black parts of rhe images are not empty, they are black pixels.