Restart everytime join server?

[jazyy_baby]

So me and my boyfriend make a world on this server together so we can play together. We finished up last night, and rejoined tonight to find our inventory is completely wiped and we had to travel from the world spawnpoint back to our house. Luckily we knew where it was, but we lost some of our items. Is there a way to change this in settings or do we just have to restart? The world itself is saved, our building and everything else is good, just our inventory... 

[_Tarna_]

Did you ever change the level name box on the panel? That sets the default world and if you change it to a name of a world that is not on the server, it will create a new world and put you in it. And since playerdata is saved in the default world, that gets reset.