The bug

When a raid is started it starts to lag all mobs in the world nether and overworld. The game was having delays of ~0.5 seconds, so you feel like all the mobs are teleporting and unresponsive. You as the player could move around normally but all of the mobs would freeze and then teleport to a few blocks away. 

What I expected to happen was...:
Mobs should work, and move around normally, and not lag out as soon as you start a raid. 

What actually happened was...:
I was playing minecraft on 1.18 on my survival world and I started a raid. I then tried to hit a pillager and I got killed by it because I was unable to hit it because my game started to be unresponsive. I first thought it was a problem with entities so put down my render distance to it's minimum but that did not work. Then I checked my CPU performance to see if it was my CPU that was having trouble and I saw that minecraft used 200% of the CPU. I tried enhancing the performance of the CPU and that didn't work. I tried to run a other CPU game that was demanding on the CPU and that worked. the game was having delays of ~0.5 seconds. So you feel like all the mobs are teleporting and unresponsive. I still have 31 GB of memory on my computer, I don't have a problem with my RAM.

How to reproduce

1. Start a level 2 raid
2. Do the raid at night
3. Do the raid in 1.18