Monster Spawner spawning spiders with potion effects

I loaded up a survival no cheats enabled world in snapshot 20w13b with the seed "-2016591598336994740" (without quotes). At the coordinates, X=413 / Y=15 / Z=-117, is a spider spawner that I made into a grinder for XP but found out as it every so often spawned spiders effected by potion effects, so far I have found one with strength, swiftness, invisibility, and regeneration I could tell what they were from the particles of the potion. I had no recource packs on at the time of playing only the new 1.14 textures that you guys made. (If I find more spiders I will give out more screenshots)