The Bug:

Goat's long jump is not affected by the jump boost effect.

Steps to Reproduce:

• Build a line of blocks in the air, with a powder snow block in the middle.
• Alter the goat's data through the use of the following command, so that it performs a long jump:

/execute as @e[type=minecraft:goat,limit=1,sort=nearest] run data modify entity @s Brain.memories."minecraft:long_jump_cooling_down".value set value 1

• →  Notice how the goat performs a long jump. Take note of how high it jumps.
• Effect the goat with jump boost through the use of the following command:

/effect give @e[type=goat,limit=1,sort=nearest] minecraft:jump_boost 100 3

• Alter the goat's data once again through the use of the following command, so that it performs a long jump:

/execute as @e[type=minecraft:goat,limit=1,sort=nearest] run data modify entity @s Brain.memories."minecraft:long_jump_cooling_down".value set value 1

• →  Notice how the goat did not jump any higher than it previously did, despite having the jump boost effect active.