In every work related org-file, I set the category like this:

#+CATEGORY: work

I then use org-agenda-custom-commands like those below to show work related content or not work related content. This works in Org version 9.5.5/Emacs 28.2, but in Org version 9.6.4/Emacs 29.0.90, both custom-commands shows the content of every file, category "work" or not.

I posted this on Reddit, and according to a user it can be reproduced in the stable version, while it works fine in the development version.
My org-agenda-custom-commands settings looks like this:

 '(org-agenda-custom-commands
   '(("p" "private"
      ((agenda "" nil)
       (alltodo ""
		((org-agenda-category-filter-preset
		  '("-work")))))
      nil)
     ("w" "Work"
      ((agenda "" nil)
       (alltodo ""
		((org-agenda-category-filter-preset
		  '("+work")))))
      nil nil)))