Go back to the File Browser and click on each folder. For example, the Pictures folder will likely have files that are counted as Documents that do not belong to your Photo Library. The Photo Library is probably greyed out in that folder because that storage is counted in the Photos section.
Are you seeing all the folders listed in the File Browser? The difference on my computer is that I have a Library section there that contains a lot of Documents and also the folders in the File Browser are listed in descending order by size, where yours appears to be more random. I am on Mac OS 15.7.3, so if you are on 15.6 as seen in your tagline, there may have been a change made in the update.