@Tatertot 

UDP port scan means the printers probably sent a packet over the network to query the router, maybe a keep alive packet?

If a device is quarentined it is prevented from commuincating over the network. The AntiVirus is dependent on the service that comes from Trend Micro. 

You can possibly contact the printer manufacturer to verify if it sends packets to the router while not actively printing. As far as the Deco you can disable "Infected Device Quarentine" and leave the malicious content filter and intrustion prevention system enabled.

@Tony 

same problem with me and not found any solution to make it work

even setting the feature off, the printers are been still caranterized.

Is there need to reboot hole system? How?

Wondering also your answer (as solution?) to get to know if the printer is sending the pakets to stay alive with connection...

this is quite normal way with certain gatgets.  

Are YOU doing something to get this working better?