Sönkkö

The odd thing is that I never save before leaving, and when i come back, everything is fine. But sometimes, every player in the server has 1000 ping or something and I stop and start the server as normally, and the world vanishes. The world vanishes only when i restart my server when the mysterious high ping is there. What magic is this

I was playing with my friend and we made an awesome world, there was modern luxury houses and all. Suddenly the server had very high ping, so I restarted the server. It didn´t take long from me to realize that all that we had done was now gone. Houses and items had vanished and the whole seed was differendt. This was the second time this happened. Anyone have the same experience? How to get my old world back?