Bug Description

When playing in a single player world, if there is a cave system below the ground level where you are playing, mobs with ranged attacks such as the trumpet skeletons in age zero will attempt to attack the player through the ground. Other mobs that do not have ranged attacks will pathfind to the blocks under the player. This leads to effects like trumpet skeletons hitting creepers and either blowing a hole through below the player to the cave where they were at if the cave ceiling / ground is thin enough, or just blasting holes in areas where the player has yet to be, and leaving entities around causing additional lag that the player may not even have access to clean up.

Did this behavior use to work in the previous version?

No, this behavior has always been the same.

Steps to Reproduce (for bugs)

1. Create a new world, as most worldgen has cave systems that generate close to the surface in multiple areas
2. Spend any non-zero amount of time standing above a known cave system within spawn range. (Can use spectator mode to check for a good spot)
3. Observe that you will hear Trumpet Skeletons attempting to attack you through the ground, even with no valid path to the player.

Logs

• Client/Server Log: Checked client log and there are no entries pertaining to this issue
• Crash Log:

Client Information

• Modpack Version: 3.1.5
• Java Version: 1.8.0_261
• Launcher Used: Twitch
• Memory Allocated: 8 GB
• Server/LAN/Single Player: Single Player
• Optifine Installed: No
• Shaders Enabled: No

World Information

• Modpack Version world created in: 3.1.5
• Additional Content Installed: None, just the included content from SevTech Ages