Trouble streaming music through mobile app

Nextcloud version: 13.0.1
Operating system: arch armv7h
nginx version: 1.13.9
PHP version: 7.2.3

I use iOS apps (e.g. CloudBeats, Flacbox) to stream music from my Nextcloud server to my phone. This used to work with Nextcloud 11, but ever since updating to Nextcloud 12, streaming is no longer working. Full music file downloading through webDAV (as well as these music apps) still works as usual. Music streaming through the Audio Player app works as usual.

Steps to replicate it:

  1. Install CloudBeats or Flacbox on iOS, log in to Nextcloud server using the webDAV URL (https://xxxxx.com/remote.php/webdav/) as shown in the web interface.
  2. Navigate to any Nextcloud directory within the app, and attempt to play a music file through streaming.
  3. App throws error (CloudBeats throws “track loading error”) or does not stop loading (Flacbox).

The output of your Nextcloud log in Admin > Logging:

{"reqId":"Ib4LQw9bP4I0mliWAD2m","level":1,"time":"2018-03-20T05:41:55+00:00","remoteAddr":"108.254.147.95","user":"winstonyin","app":"admin_audit","method":"GET","url":"\/remote.php\/webdav\/Storage\/Music\/Albums\/ABBA\/ABBA\/01%20Mamma%20Mia.mp3","message":"File accessed: \"\/Storage\/Music\/Albums\/ABBA\/ABBA\/01 Mamma Mia.mp3\"","userAgent":"Flacbox\/2.0 (iPhone; iOS 11.2.6; Scale\/2.00)","version":"13.0.1.1"}
{"reqId":"aguCYbSwdHVkFAXphPCg","level":1,"time":"2018-03-20T05:41:58+00:00","remoteAddr":"108.254.147.95","user":"winstonyin","app":"admin_audit","method":"GET","url":"\/remote.php\/webdav\/Storage\/Music\/Albums\/ABBA\/ABBA\/03%20Tropical%20Loveland.mp3","message":"File accessed: \"\/Storage\/Music\/Albums\/ABBA\/ABBA\/03 Tropical Loveland.mp3\"","userAgent":"Flacbox\/2.0 (iPhone; iOS 11.2.6; Scale\/2.00)","version":"13.0.1.1"}

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "nc.winstonyin.com",
            "localhost",
            "feynman",
            "192.168.1.123"
        ],
        "overwrite.cli.url": "https:\/\/nc.winstonyin.com",
        "dbtype": "mysql",
        "version": "13.0.1.1",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 0,
            "timeout": 0
        },
        "mail_smtpmode": "smtp",
        "mail_smtpauthtype": "LOGIN",
        "mail_smtpsecure": "ssl",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpauth": 1,
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "465",
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "enabledPreviewProviders": [
            "OC\\Preview\\PNG",
            "OC\\Preview\\JPEG",
            "OC\\Preview\\GIF",
            "OC\\Preview\\BMP",
            "OC\\Preview\\XBitmap",
            "OC\\Preview\\MP3",
            "OC\\Preview\\TXT",
            "OC\\Preview\\MarkDown",
            "OC\\Preview\\Movie"
        ],
        "loglevel": 0,
        "maintenance": false,
        "updater.release.channel": "stable",
        "theme": "",
        "skeletondirectory": ""

/var/log/nginx/access.log:

108.254.147.95 - - [20/Mar/2018:13:54:52 +0800] "PROPFIND /remote.php/webdav/ HTTP/2.0" 207 599 "-" "Flacbox/2.0 (iPhone; iOS 11.2.6; Scale/2.00)"
108.254.147.95 - - [20/Mar/2018:13:54:52 +0800] "PROPFIND /remote.php/webdav/Storage/Music/Albums/ABBA/ABBA/01%20Mamma%20Mia.mp3 HTTP/2.0" 207 607 "-" "Flacbox/2.0 (iPhone; iOS 11.2.6; Scale/2.00)"
108.254.147.95 - - [20/Mar/2018:13:54:53 +0800] "GET /remote.php/webdav/Storage/Music/Albums/ABBA/ABBA/01%20Mamma%20Mia.mp3 HTTP/2.0" 206 48546 "-" "Flacbox/2.0 (iPhone; iOS 11.2.6; Scale/2.00)"
108.254.147.95 - - [20/Mar/2018:13:54:54 +0800] "PROPFIND /remote.php/webdav/ HTTP/2.0" 207 599 "-" "Flacbox/2.0 (iPhone; iOS 11.2.6; Scale/2.00)"
108.254.147.95 - - [20/Mar/2018:13:54:55 +0800] "PROPFIND /remote.php/webdav/Storage/Music/Albums/ABBA/ABBA/03%20Tropical%20Loveland.mp3 HTTP/2.0" 207 615 "-" "Flacbox/2.0 (iPhone; iOS 11.2.6; Scale/2.00)"
108.254.147.95 - - [20/Mar/2018:13:54:56 +0800] "GET /remote.php/webdav/Storage/Music/Albums/ABBA/ABBA/03%20Tropical%20Loveland.mp3 HTTP/2.0" 206 48530 "-" "Flacbox/2.0 (iPhone; iOS 11.2.6; Scale/2.00)"

Hi,
I had a similar issue with video streaming, and as you seem to run NC on a 32bit OS, the quickfix I propose here below might work for you :

Let me know.
Regards,
Raph