To replicate this glitch, simply start up a new minecraft world in version 1.14.2, and create a Nether Portal. Then, wander around a little. You may see chunks wherein the zombie pigmen and such don't move AT ALL. This is the glitch. Also, minecarts freeze upon entering such chunks. The only entity that CAN move in such chunks are players. __In addition, this glitch will randomly affect different chunks each time you load the minecraft world.