Drop all coming to the router - yes as stupid as it sounds

RouterOS Beginner Basics
1

Hey!
I am trying to setup a rule to drop all traffic coming to my router.
It’s for test purposes only but I can’t get it to work.

My router is on 10.0.4.1/24 and my host is at 10.0.4.248/24.
However when I create the following rule with the “drop” action in the firewall, it doesn’t want to work at all… and I don’t understand why.
Note : Would it be possible that it is my ARP table on my PC and they both communicate through mac?

Could someone guide me on how to achive this simple thing.
Later on I want to block my clients in a guest network to ping between them.

Thanks in advance!