musescore.com playback is bugged

When playing a larger file, I'm encountering quite a few issues with loading and playback:
* MuseScore Audio never loads (I waited multiple minutes for this to load)
* Only Synthesizer works
* Only MuseScore audio works
* No audio from either audio source
* The loading bar doesn't go all the way to the left
* Playback is not synced to the correct measure after changing audio source
* Playback is not synced to the correct measure after selecting a different measure
* Pausing does not fix playback sync issues.

I have a 2 min video file but it's way too large to send here, even when downgraded to 480p.