Same happens to me with my brother. Im in Abu Dhabi and my bro in Spain and is imposible to see each other hosted game. Even switching between Gamespy and Steam does nothing.
So fustrating issue.

Hello??? Are you guys even going to acknowledge that this has been received?? Any chance of getting an update or at least some kind of reply??? Anyone??

Hello, can you connect directly via remote button (bottom left corner, right next to Join button)?

It looks like the server is behind the NAT and it's not visible for Steam services. If possible, try to open/redirect game port + ports for Steam to your machine with server.

I am having the same issues. I have been playing the game just fine until now. Now my friend can't join and we see each other's ping as 2500. Remote join won't work either. The problem happens on Steam and GameSpy. When I launch a game on Steam, my friend can only see it on the GameSpy server browser. Any other game works great and our connection is excellent. I have opened up ports 2302-2305 for Arma3,and 27016 for Steam on my router. I have verified files on Steam, re installed the game, re installed Steam. I have also tried using other programs like Hamachi. I also found many forums about this same issue happening with Arma 2 as well but I have yet to find one with a solution.

Same here. I also posted on Steam forums and there are more users whith the same problem. I posted a link to the feedback tracker on the Steam forum also.
The issue starts since update 1.18. Thats at least when I noticed.
Please devs try whatever you can with this due to is novadays imposible to play with some friends due to this issue.

Ok, so you can see each other in browser (so it's not problem with master server) but you can't connect, even by using remote (which bypasses the browser), so it looks like it's the connecting itself. If I'm reading this right, this happened since 1.18, it was fine on 1.16?

Is this server on public IP (is it DS) or are you creating the session in the game? Have you tried different ports (to rule out conflict with other services)?

We cannot always see each other in the server browser. We can only see each other in the browser if we use Hamachi. Normally we cannot even see each other's game in the browser. We are creating the session in the game. Remote join will not work. Creating the session using the other ports like 2305 didn't work either. The problem started happening with the update that brought in the Steam server browser.

GEORGE: We cannot see each other in browser. That's my problem and the other people reporting the same issue on Steams forums stated the same.
I create a game and my friends cannot see my hosted game. Same happens when they create a game; I cant see them on server list browser neither if I search by they name.
I hope that clarification could help you guys.

I'm actualy in the same situation ... When my friend or me create a game, none of us can find each other ... I dont realy know witch version started that mess ... but I know that when Gamespy were still online we did not have that problem ... I unistalled and reinstalled the game twice nothing changed ... I'm still able to connect to public dedicated server ... but not on simple private game hosted by ourself on the same computer that we play on ... we cannot join or even see each other in the server browser ... I checked the ports and arma 3 is set to all ... maybe I'm wrong (never been a pro in ports and stuff) I'm using a simple router Cisco E1000 with Windows firewall ... every other game that I play still working fine