VPN is never enabled in a normal windows, only in private mode. Turbo is not enabled either. edit I see VPN can be enabled in normal mode. But it wasn't so that wasn't the issue /edit
I just noticed that when I use private mode with VP turned off I do get the right IP. In normal mode I tried to turn my extensions off one by one to see if one of them was the culprit. This had no effect and I still got the wrong WAN IP.
So there's something about normal mode that causes this. I'd like an Opera developer to way in on this issue. It's kind of creepy.
While writing this I think I've solved the problem. Here's how: I enabled VPN on the Opera settings page. This changed my IP as it's supposed to do. After disabling VPN I now get my real IP in normal browsing mode.
What the heck happened here?