Not sure whether this issue is still being addressed. Struggling to connect to servers and they are a bit touch and go with browser querying (50% of the time I can see them and the rest of the time I can't). Any servers that have the port of 27016 seem to be less likely to display. If I manage to get into the game on the same server with port 27015 then I seem to be able to join the other. I am assuming it is a Firewall issue.
All those in favour of turning the firewall off say I: