It seems that mv 4.1.1-SNAPSHOT ignores the world-container setting from bukkit.yml as you can see here:

minecraft@multivac:/data/minecraft/servers/pandora$ grep level-name server.properties
level-name=pandora
minecraft@multivac:/data/minecraft/servers/pandora$ grep world-container bukkit.yml
world-container: worlds
minecraft@multivac:/data/minecraft/servers/pandora$ ls -l worlds
total 0
drwxr-xr-x 4 minecraft minecraft 109 Jul 11 09:08 end2
drwxr-xr-x 6 minecraft minecraft 134 Jul 11 09:08 minera2
drwxr-xr-x 12 minecraft minecraft 228 Jul 11 09:08 pandora
drwxr-xr-x 8 minecraft minecraft 159 Jul 11 09:08 pminera
drwxr-xr-x 6 minecraft minecraft 134 Jul 11 09:08 pnether
minecraft@multivac:/data/minecraft/servers/pandora$ ls -l |grep pandora
drwxr-xr-x 7 minecraft minecraft 151 Jul 11 09:03 pandora
minecraft@multivac:/data/minecraft/servers/pandora$

When trying to (re)import those existing worlds:

mv import pminera normal
[09:12:08 INFO]: FAILED.
[09:12:08 INFO]: That world folder does not exist. These look like worlds to me:
[09:12:08 INFO]:

That problem occurs since updating on paper-1.16.1-86 (mv-4.1.1) and worked flawlessly (on every update) before. Please check and fix.

Tested in 1.19.4 with PaperMC

The correct format is:

settings:
  world-container: worlds/

This doesnt Work:
world-container: worlds
or
world-container: /worlds
or
world-container: /worlds/

Seems to be a Spigot issue: https://hub.spigotmc.org/jira/plugins/servlet/mobile#issue/SPIGOT-5824

yea, its mention to be unlikely to be fixed. It also states that you can use command line flags of --world-container, -W, --universe, --world-dir Any of those, they're all aliases.

Thank you for pointing me to the spigot ticket. Everything works as expected now.

Paper seems to be doing something.. PaperMC/Paper#3878

Seems like paper fixed this issue, so I will be closing it. See: PaperMC/Paper#3873