Yes I've had this problem so many times now, also, sometimes when you kill yourself (Or someone kills you), your HP bar flashes, but you don't actually die, you're also de-synced, other players can't see you, and you have to jump of somthing high to kill yourself properly. It's very odd.
It is when u have some connection problems ir server crashes, but get online after few seconds. When u get message Lost Connection from client and u connect automaticately, then this bug shows himself