No Standard Playlist creation possible

[ghost]

Expected behavior

Clicking [+] in the sidebar opens the field to naming a new Standard Playlist.

Actual behavior

Nothing happens under Nextcloud 13.

Steps to reproduce the behavior

1. Under NC13, open the sidebar.
2. Select Playlists.
3. Click on the [+] button.

Additional information (optional)

Works with Nextcloud 12.

Server configuration

PHP version:
7.1.11

Nextcloud/ownCloud version: (see /status.php)
Nextcloud 13.0.0.11 (13.0.0 RC 2)

Updated from an older Nextcloud/ownCloud or fresh install:
updated from 13.0.0.10

Audio Player version: (see /settings/apps)
2.2.4

Where did you install Audio Player from:
Git master

Are you using external storage, if yes which one: local/smb/sftp/...
no

Are you using encryption: yes/no
no

Client configuration

Browser:
Firefox Quantum 57.0.4-64
Samsung Internet 7.0.10.21