Ok, lets try this. set up IP address reservations for the both consoles ON the router. I would wired connect the consoles for this. If you choose wireless, you'll may need to set a different IP address reservation for the wireless connection. Clear any static IPs on the consoles and set them up for dynamic or auto obtain IP/DNS addressing. If Sony has any kind of power button reset method to reset the consoles, lets do that and fully power them OFF. For xbox, if you hold the power button untill it shuts off, this clears it's caches using this method.
Besure uPnP is enabled and NAT Filter is set to OPEN on the router. Save settings and then power OFF the Modem and Orbi router. Power ON the modem and let it sync. Then power ON the Orbi router. Let it come to ready.
Power ON the sons console first. Check NAT status with in the consoles networking settings. I presume it has this some place. I don't use PS so Just kind of going on what Xbox has. I presume you should see NAT Type 2 here. This is fine. Launch his game and check for any NAT status or check the chat condition.
Power on your game console and check NAT status on the console. Then start your game and check status here.
If all is cleared, there shouldn't be any problems getting into games and chat should work.
