Playsound not working in datapack

I have a little troll datapack to play a creeper sound behind the player. it checks the player's rotation and then plays a sound behind them. however, it first plays footstep sounds and then the creeper hiss. but only the first sound plays, and the ones in scheduled functions dont. i know the functions are getting run because the tag is getting removed at the end, but the sounds wont play, even though im doing execute as @a to workaround scheduled functions not working with @s
anyone know whats wrong?