Bukkit

My first problem was when i added new world a i wanted to delete it, it was still there. I deleted world and /lobbyapi remove world and the block was still in menu but it didn’t teleport you. I had to delete plugin and start over. Then when i set everything right, icons, slots, setspawn, i restarted server and it was again as default, items was glass names was default too and spawn was at the wrong place. Even the world selector didn’t work. But in the config on FTP was right, everything was set up as i did but it didn’t worked at the server. I have Spigot 1.15.2. Can you help please.