Something is fucked up with Apple Music streaming playback; it may be Bluetooth specific or may not be. In nearly every song I stream, whether it's from my iCloud library or Apple Music itself, there's a stutter at exactly the 15 second mark in whatever song it is; the stutter is different every time but when it occurs is consistent.

There are also inconsistent stutters throughout songs.

iPhone 13 and 2nd gen AirPods Pro, if it's relevant.

I've filed a feedback but Apple feedback is a black hole these days.