Playback does not start on file open when default Windows audio output device is switched

Important Information

Provide following Information:

• mpv version: mpv 0.34.0-185-g0197729949
• Windows Version: 10 21H1
• Source of the mpv binary: Windows builds by shinchiro (releases and git) | https://sourceforge.net/projects/mpv-player-windows/files

Reproduction steps

I have separated my front and back audio output in the Realtek Audio Console. Everything works fine, if I leave the default output in Windows on the back audio jacks. But if I switch my default output in Windows from the back to the front output jack (Settings --> System --> Audio) and play a file, the file opens, but the playback does not start.

It seems that the audio thread gets shut down and not restarted again (see attached log file).

Expected behavior

The file starts to play right away on the default audio output.

Actual behavior

MPV opens the file, displays the first frame but does not start playing it. Pressing play/pause button or keyboard shortcut has no effect. Playback only starts after seeking, either on the osd or via keyboard shortcut.

Log files

log-front.txt
log-back.txt

Start by comparing log-front.txt and log-back.txt, then reproduce the issue on Windows 10 by switching the default output between the back and front audio jacks before opening a file. Done means playback starts immediately on the selected default output and play/pause works without seeking.