- Fully remove the Bluetooth pairing
Settings → Bluetooth & devices → remove the phone (not just in Device Manager, which can leave orphaned audio stubs).
- Restart audio services in this order: Open Run menu and type services.msc > hit the Enter key
RPC → Windows Audio Endpoint Builder → Windows Audio.
- Unhide your real output device
Right-click speaker icon → Sound settings → More sound settings → right-click empty space in Playback tab → check "Show Disabled Devices" and "Show Disconnected Devices" → find your HDMI audio device → Enable → Set as Default.
- Check Device Manager
Sound, video and game controllers → look for "Intel/NVIDIA/AMD Display/HD Audio" → if disabled, Enable; if missing, Uninstall it then Action → Scan for hardware changes.
- Run the troubleshooter
Win+R → msdt.exe /id AudioPlaybackDiagnostic
- Reinstall the audio driver fresh.