Hi, Matthew, and welcome to the forum!
By "ARP," I'm assuming that you meant "ARC." Also, you mentioned a couple of items connected to HDMI #1, so I'm guessing that's just a typo. You mentioned that your AFN decoder box is connected to video ports, so if it's not connected to an audio input on the TV, you won't get audio from it.
The first thing that I'd try is to connect the ARC HDMI jack on your Panasonic TV to the "OUT (ARC)" jack on the YSP-2200. That is the jack to use with ARC.
The second thing that I'd try if the above didn't work is to connect the optical audio output from the TV to one of the optical audio inputs on the YSP-2200. I say that because I'm not an ARC expert (I don't use it), and I don't know if your TV can output audio over that connection from other things connected to it.