Raspberry Pi 400 HDMI Audio Works One Minute, Then Drops Out Completely

I’ve been using my Raspberry Pi 400 as a lightweight media center connected to my TV via HDMI. The video output is always perfect, but the audio keeps cutting out randomly after about 5-10 minutes of playback. When the audio drops, the TV still shows the video perfectly, but there’s just silence. I’ve tried different HDMI cables and switched TV inputs, but the problem persists. I’m running the latest Raspberry Pi OS with all updates applied, and I’m using VLC and Kodi for playback. Both apps show the same issue. Rebooting the Pi fixes it temporarily, but it’s a pain to do every time. I checked the audio output settings, and it’s correctly set to HDMI, but sometimes it switches to analog on its own, though the sound never actually comes through the headphone jack. Has anyone seen this kind of flaky HDMI audio behavior on a Pi 400? Is there a way to force the audio output to HDMI permanently or monitor what might be causing it to drop? Also, would using an external USB sound card be a reliable workaround for this kind of issue?