Hi. I'm facing the same problem as you. Particles don't work. Which is related to the version of the game and the world where particles are called. Namely, on version 1.12.2, particles will work in any of the worlds. Example "particle firework %player_x% %player_y% %player_z% 0.1 0.1 0.1 1 100 normal" At the same time, on version 1.16+, you will need to change this command to "execute in minecraft:superiorworld run particle firework %player_x% %player_y% %player_z% 0.1 0.1 0.1 1 500" This is an obvious bug, but at least it is possible to fix it.
@unknown
"You not understanding a change doesn't make it a bug."
I have never encountered particle problems for 1.12 and below before, which is why I consider it a bug when in early versions particles were executed in all worlds and now only in World and you have to use a separate command for particles in another world.