I'm not on the beta, I'm on release 7.63 but I also experience this issue. My source to the web is via WiFi, I still have a LAN port, but no hard cable ran. mIRC will find the right adapter and connect to IRC fine, but it gets confused sometimes on uPnP requests, and even my uPnP Daemon doesn't resolve this issue like it used to before in the past. Turns out if I do a localinfo -h, it winds up resolving to my LAN adapter's IP address which literally goes no-where (not even a LAN cable plugged into the back) instead of my WiFi adapters internal IP, which makes sense on why uPnP fails when it's trying to ask my router for a port forward to the wrong adapters local ip.