Android, iOS: Headers are not sent together with the request in MediaPlayer

When feeding data from an HTTPS stream directly to a QML-instantiated QMediaPlayer
the media player stays in the playing state while not playing any of the feeded data
when on Android and iOS. The same code works for both GNU/Linux and SailfishOS.

Sample application:
http://github.com/fredldotme/harbour-owncloud/tree/accounts+sync

C++: https://github.com/fredldotme/harbour-owncloud/blob/f7c86c71c5d37a9477a237781f7f4d6ae74659a4/src/app/src/webdavmediafeeder.cpp
QML: https://github.com/fredldotme/harbour-owncloud/blob/f7c86c71c5d37a9477a237781f7f4d6ae74659a4/src/app/qml/qqc/pages/browser/FileDetails.qml#L79

Build config:
CONFIG+=noadditionals CONFIG+=quickcontrols

Output:
-----------------------------------------
Android:

D GhostCloud: qml: clicked @ 0
D GhostCloud: QNetworkRequest getOcsRequest(const QNetworkRequest &, NextcloudSettingsBase *)
D GhostCloud: headers ("Authorization", "OCS-APIREQUEST")
D GhostCloud: qml: AV preview
V MediaHTTPService: MediaHTTPService(android.media.MediaHTTPService@4f879f2): Cookies: null
D GhostCloud: qml: playback state 1
V MediaHTTPService: makeHTTPConnection: CookieManager created: java.net.CookieManager@61fd843
V MediaHTTPService: makeHTTPConnection(android.media.MediaHTTPService@4f879f2): cookieHandler: java.net.CookieManager@61fd843 Cookies: null

-----------------------------------------
-----------------------------------------
GNU/Linux:

qml: clicked @ 0
QNetworkRequest getOcsRequest(const QNetworkRequest&, NextcloudSettingsBase*)
headers ("Authorization", "OCS-APIREQUEST")
qml: AV preview
qml: playback state 1
qml: playback state 0

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