The battleye client has stop responding on servers where it would have worked fine few days back.
I'm still waiting on a issue to be resolved:
http://feedback.arma3.com/view.php?id=13999
Not sure if the older issue would impact on this battleye client issue.
All I have changed is my router. I suspect it should still work fine as Arma2 has no troubles connecting to servers, As far as I'm aware arma3 and arma2 share the same ports.