Sound output from all applications garbled when MuseScore is running

Summary

Whenever I launch MuseScore (with native Pulse audio output enabled), all the audio coming out of my HDMI audio becomes garbled; even audio from other applications (e.g. VLC).

Closing MuseScore immediately restores audio quality. Or, moving MuseScore to a different sound card (e.g. my non-HDMI sound card) also restores HDMI sound quality.

Environment

• Fedora 31 (up-to-date as of 2019-01-19)
• PulseAudio 13.0 (pulseaudio-13.0-1.fc31.x86_64)
• MuseScore 3.3.4 (mscore-3.3.4-4.fc31.x86_64) configured to use native Pulse audio output in preferences
• AMD Radeon RX 580 with HDMI audio output to LG 27UD88-W
  • 0d:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere HDMI Audio [Radeon RX 470/480 / 570/580/590]
  • (My motherboard also has a AMD Starship/Matisse HD Audio Controller which does not exhibit this problem. Only the HDMI audio is affected.)
• pa-info.txt
• pa-log.txt

Steps to reproduce

(Video illustrating issue)

1. Use HDMI audio (AMD Radeon Ellesmere HDMI Audio)

2. Start audio playing (e.g. with VLC)

   Observe that audio output sounds fine

3. Open MuseScore (ensure it's configured for native Pulse audio output)

   Audio becomes garbled, even without composing or playing any music in the application.

4. Close MuseScore

   Audio returns to normal.

What is the current bug behavior?

Audio becomes garbled while MuseScore is running.

What is the expected correct behavior?

Audio stays normal, and all application audio is correctly mixed.