2 Different worlds with different Online Mode

CraftBukkit 1.15.2 server:

Hey there! I have a question: I moved one world to my craftbukkit folder, deleting the other folders, and today i found out a really weird thing.

Let's call the world i moved into the folder World A, and the other one World B.

When in my server.properties online-mode is set to true, i get World B, and when online-mode is set to false, i get World A. There's only one world folder on my server folder (including nether and end, too)

My plugins are: Clearlag, Vault, ViaBackwards, ViaRewind, and ViaVersion.

I want to save both worlds, and use World B with online-mode=false, and viceversa.

Thanks for your help ^^

I don't understand why this is this way, it's super weird to me :/ guess i can't play my World A on online mode

EDIT by Moderator: merged posts, please use the edit button instead of double posting.