Audio and video attachments looping in Apple Watch notifications

I’m building a small application that detects various kinds of classified sounds and sends a notification to home assistant.

Everything is working well, but when I send a WAV audio file or an MP4 video (waveform) file as a standard attachment, it loops when played back on the Apple Watch (26.2 newest OS). I can’t find any configuration flag that would allow me to disable this.

Is this expected behavior, or is this a bug? (Or, even more likely, does this happen for anyone else?)