I also have this exact same issue. I can rarely make it through one game without the screen freezing for approx. 10 seconds, then the transition screen, then disconnecting and giving the port forwarding error. I can play Hardline just fine, or BF3 just fine, but not BF4 immediately after the spring patch. No lack of hardware or working GPU drivers on my end, as well as proper port forwarding. Something in the Spring patch jacked my game and broke it. Please investigate this EA and provide a solution or a fix for your latest "fix". It is extremely annoying not being able to play a game I payed $110 for.
hopefully the upcoming server downtime will fix, kind of doubt it though
