Unable to Add Queue to Playlist

1. Add songs to Queue
2. Navigate to Playlist
3. Edit Playlist
4. Click 'Insert from Queue'

What happens?

Nothing Happens :), Syncing changes stuck in a loop forever.

What is expected?

Playlist properly updated

Context

• Self hosted funkwhale instance

Funkwhale version(s) affected: 1.1

• Reproduced on both Firefox and Chrome (including incognito mode to rule out cookies / plugins)

Server Logs (not that helpful :( )

funkwhale    | 2021-03-15 21:41:48,327 django.request WARNING  Bad Request: /api/v1/playlists/2/add/

Reproduce Example

funkwhale-2021-03-15_15.38.42.mkv

Console Error Message