This has happened a few times now. I've noticed that my characters have been disappearing on public servers. My friend has been having the same problem. Sometime, we would jump from one server to another and we both lose our characters. Sometimes only one of us would lose them. While playing, we would have the public hive servers filter on so no private hives would show. I've checked a few times on the servers we've been joining with only one of them being a hardcore server with first person only out of many occasions when the characters were wiped.