Same here. My wife and I have a couple of friends (also married) that are all facing this problem. One of key reasons that they got DA:I was to be able to play four-man with us. As it is, it seems like we can only get it to really work with two at the same time reliably, sometimes 3. This was a one-off where I was in the DMZ, the router was forwarding ports to my wife and I'm not sure what our friend's configuration was.
This is pretty bad. ☹️ It makes me have a major sad. I was really looking forward to playing as a geeky double-date.
