iOS pausing music during workouts

I upgraded to iOS 15.3.1 on my iPhone 11 recently, and now the music (via Spotify) pauses every single time my workout app (Hevy) plays an audio cue. This is super annoying, and all the resources I've found so far give solutions that involve Apple Watch - which I do not own.

I've tried disabling notifications in Hevy, but they still trigger when the app is open (which it is during workouts).