Why are files sorted by size range when browsing to upload a file?

When browsing my macbook's hard drive to upload a file (e.g. to an email), files appear sorted by size range (e.g. 100MB to 1GB, then 10MB to 100MB etc.). Clicking on, say, "Date added" to sort them by that parameter only affects the files under each size range, not the entire folder.

This does not happen in a regular Finder window, only when clicking the "Browse" button from upload menus.

It has started happening after uploading to Big Sur and it's a bit annoying, as I regularly download files from one place and then re-upload them to another, and I'm used to having the most recently downloaded file on top of the list in the upload-browser window.

Hope my description is adequate and that someone can help me out on how to get rid of this.