I was just randomly disconnected from Overwatch servers on the Steam version of the game. The lost connection symbol suddenly appeared in the match around 10-15 seconds before I was kicked back to the menus, and in that time the game was still perfectly synced. There was no increased latency, players were still moving, shooting, and casting abilities like normal. After I got kicked back to the menu, it gave me an error BN-564. I tried restarting the game and reconnecting twice, and it simply got stuck loading. It wasn’t until I restarted Steam entirely that I could reconnect to the servers. During all this time, my internet remained undisrupted.
Perhaps relevant is people on my friends list were unable to see me online on the game until after I restarted Steam. Now they can. Though that had been a persistent problem for several days and over several restarts of both Steam and my computer.
Edit: It’s now happened about 6 or 7 times, and I’ve lost 2 entire endorsement levels as a result. It’s consistently the same problem. Lost connection icon appears after anywhere from 15 minutes to an hour into the session; game still runs like normal for several seconds, then I get dropped from the servers. Afterward I’m unable to reconnect to the servers until I restart Steam. I verified the file integrity in Steam, and it came up with 0 issues.