For whatever reason, all of the images on the archive now seem to have a slightly different filesize and a slightly different image hash from what the actual images on 4chan do/did

You can download an image off of a current /v/ thread (say this the OP image here: https://boards.4channel.org/v/thread/640320202 / https://is2.4chan.org/v/1686513022851627.png / hash: ceb6T3DlA6WH9lxxp6ImLA) and it will have a different filesize, a different hash (and as a result no results will show up here on arch.b4k.co if you search by hash) vs the same image arch.b4k.co: (https://arch.b4k.co/v/thread/640320202/ / https://arch-img.b4k.co/v/1686513022851.png / hash: 95IXBfWOf-YJavsGwZnkew)

This even seems to be retroactive: I can't search a file I have on my computer i've posted to /v/ in the past via the file hash search now, because now the hashes of those images is different from what I have saved locally, even though the file should be the same and I could get results via searching that file by hash before (and if I search by filename instead, it works fine)

tl;dr:

arch.b4k.co seems to have changed the all of the images in the archives which now breaks searching by hash using the original 4chan uploads.

What's going on here? Can this be reversed? Do images on the archive have extra lossy compression now?