I am playing the newest snapshot of Java 1.17, 21w14a.
I'm exploring the deepslate caves in the negative Y coords, and I am exploring a mineshaft within those caves. I destroyed a Cave Spider Spawner and the particles will just linger after it is destroyed.
I tried searching for a little bit and could not find a bug report similar to this. It's not a huge problem, it doesn't break the game or anything, but it most likely isn't intentional.
Notes:
-Happens anytime a spawner breaks
Dupe of MC-222561