Recently, I was getting random disconnects when the expansion released. I think it’s overloaded servers or someone DDS attacking Blizzard servers, or some bug.
Either way, it’s not an opposing player almost certainly because the player would have to have your IP address. And, in your case, you tried with different clients with different IPs, pretty much solidifying it’s not an attack on your IP, but rather something wrong on the server side.
It’s been very finicky in the last few days.