^{Updated from EVGENSYPERPRO}
Summary:
Horses, donkeys and mules after updating 1.19.50 can automatically walk up 1 block without a player, without the need to jump (until 1.19.50 they could automatically walk up one blocks only with the player). Since the carpet has a hitbox, horse, donkeys and mules should not walk up block with a carpet. It also creates parity with Java, and also breaks all the corrals with carpets built before 1.19.50.

Steps to reproduce:

1. Place any block 1 block high.
2. Place the carpet on block.
3. Summon the horse, donkey or mule.
4. Push a mob through a block or saddle and try to ride up a block without jumps.

Observed results:
Horses, donkeys and mules can walk up blocks with carpets.

Expected results:
Horses, donkeys and mules can not walk up blocks with carpets (since the height of the obstacle is more than 1 block).

Original description:

Fenced in horses can now escape by jumping onto carpets when the carpet is placed on the fance. To reproduce:

• put a horse in a fenced in area
• place a carpet on top of the fence
• nudge the horse onto the carpet