In order to optimize the server performance, several changes have been made which could alter the way mob farms work. The most notable changes are as follows:
The hostile mob cap is 15 hostile mobs per player.
The soft despawn range is 28 and the hard despawn range is 96.
The ticking view distance is 3.
The server attempts to spawn hostile mobs every 4 ticks.
If more than 4 iron golems are alive within a radius, nearby villages will not spawn any new iron golems.
Villagers tick significantly less often when the tps is below 19.
Zombies are not aggressive towards villagers when the tps is below 19.
Non-player entities cannot enter portals.
A chunk will only save up to 1 hopper minecart. Any extras will despawn when the chunk is unloaded.