How to troubleshoot if Pfblockerng Category block not working
Currently we are working on 21.05.2-RELEASE, if your category not working as expected, then you have to ensure that you are getting same output after selection the category. then list of the package should be list here as you can see. we choose Shalla black list and it shows the count of packages.
If you are not getting output like that with count of unique files then you have to disable DNSL then remove package and reinstall, then try again, once it shows then count it will works