Playsound: If area effected by /playsound is greater than attenuation distance then volume resets back to minimum value after having gone to zero

Procedure:

Place repeat command block with delay in ticks 5 always active unconditional with the command:

/playsound note.pling ~~~ @a[r=60] 2 1 1

Start walking away.

Expected result: sound should get quieter until volume reaches 1 and then should stop entirely once you have made it more than 60 blocks away

 

Observed result: sound drops down to 0 instead of 1 before abruptly resetting back to 1 at exactly 32 blocks away, and stays like that until you clear the 60 block radius at which point it goes back to 0 again as expected.

 

I feel like this is just a underflow issue but it may be something more complex

This is a problem because it limits the range of the sound to 32 blocks.

 

This effects be because I'm trying to make a system that warns the player when a fireball is approaching and the movement of the fireball is so fast that at 32 blocks you only have a few seconds of warning