Cancel alert music

Hello,

I have an iPhone 5S.

I have chosen a longish music as my alert/reminder. Till recently when the alert got triggered I could cancel it (the music) by pressing any of the volume buttons. Past few weeks (possibly since I upgraded the OS), I am not able to stop it abruptly.

It is very annoying as the entire music plays out no matter which button I press or swipe.

Appreciate help/advise.

Thanks in advance.

Sanjay