Origins has several races which are smaller than normal player-size. This moves the camera closer to the ground and zooms it in to show the proper perspective of a smaller player. When you install Alex's Caves, this is forcibly reverted back to the normal player-camera height and position, even tho the player model remains small and unchanged.

To reproduce:

1. Create a new blank Curseforge profile for 1.20.1 and forge 47.2.0
2. Install latest Origins, Pehkui and Medieval Origins Revival
3. Launch game, create a world, and choose 'Pixie' as origin. You are now very small, and standing next to a single block, it looks like a huge wall.
4. Exit game and install Alex's Caves.
5. Revert the auto-installed Citadel to 2.4.5 because otherwise game crashes on launch.
6. Load back into game and same world and now your player-camera is forced back to a normal 2-block height and you don't seem small anymore. If you press F5 for third-person view, you can see your character is a little tiny player-model (if you look down sharply) but the player-camera is forced into the wrong position.

This is resolved with the new 1.0.5 release of Alex's Caves along with Citadel 2.4.7