The Command Block plugin you have does not seem to block commands, not even the default ones. Or is it something Im doing wrong?
https://umod.org/plugins/command-block

I'd need more information in order to help you, but it sounds like you do not have the plugin loaded.

Not all commands are sent to the server, some aren't handled the same way as others either. I'm not sure that the commands you configured are sent to the server as normal commands.