TV13 and firewall detection question *urgent*

Hello all

A little question to know if it's a normal process

I've added a computer on my local network, and i have had just now a popup of my firewall to say me than TV13 would his connect to this computer (UDP 5353, mdns ?)

tv13 wasn't open, just the service was 'up'

could you say me if it's normal please ?

thanks a lot