The sound will execute properly, unless the player is moving with key "A", the direction does not affect this bug. If the player is moving with "A" the sound will rapidly decrease until the player stops pressing the key. You can bind the key to any other and this will still happen, the only exception is when a wall stops the player from moving. You can move towards the same direction with any other key and this won't happen! hence the title.

Reproduction steps:

Run the following command on a redstone clock:

/execute as @a at @s run playsound minecraft:entity.player.levelup master @s ~ ~ ~ 1 1 1