As far as I understand, audio cards hold a buffer of the audio that should be played at any time. If the CPU can't keep up producing new audio, it will loop to the beginning of the buffer. My guess is that when you suspend, the CPU stops producing new data before the audio card stops consuming it. And that's why you hear the last part for a short instant.

It also happens on my devices, and it's always happened on all my previous devices as far as I can remember.

Disclaimer: this is based on my understanding + a lot of suppositions. It might not be accurate.

It's probably just your computer stuttering while trying to change states. Perhaps pause your audio before you suspend it. I don't think it's necessarily an indication something is wrong.

I suppose if you do find a fix for it then I'm curious but it's nothing that I personally would be worried about.

Probably unrelated but just in case: Happens on Manjaro when I hibernate while a game is running