Storing variables on SMP server with NBT does not work

I have a command, that sets a destination (for a portal) which is in theory supposed to save a variable to commandsender's NBT.

The variable is then used by an item, which makes a portal to the said destination.

The variable is saved and loaded properly in single player, but on the server it does not load it (is it using a different set of objects?)

I also tried a global variable in the main class, but that doesn't work either (server is probably using a different set of objects)

Saving:

@Override
  public void processCommand(ICommandSender icommandsender, String[] astring)
    {
        try
        {
            if (astring.length >= 1)
            {
                ((EntityPlayer)icommandsender).getEntityData().setString("destination" , astring[0]);
                BungeeCordForgePortals.destination = astring[0];
                ((EntityPlayer)icommandsender).addChatMessage("Destination set to " + ((EntityPlayer)icommandsender).getEntityData().getString("destination"));
            }
            else
            {
                ((EntityPlayer)icommandsender).addChatMessage(getCommandUsage(icommandsender));
            }
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }

Loading:

this.destination = player.getEntityData().getString("destination");