localized assetTitle for makeAssetDownloadTask/assetDownloadTaskWithURLAsset doesn't work on iOS10.3

Note: The below is for iOS 10.3.3. On iOS11.4.1 all is confirmed to work.

I'm downloading HLS+FP content by using an AVAssetDownloadTask created by calling AVAssetDownloadURLSession.makeAssetDownloadTask(asset:assetTitle:assetArtworkData:options).
I set a japanese string as the assetTitle. (don't seem to be able to post Japanese text here... )
The task is created, i call task.resume() but there is no progress.
The task is created as I can find it with AVAssetDownloadURLSession.getAllTasks()
The state of the task is running.
But, there is no progress on the download.
Using the exact same code but I instead set assetTitle to "Roasting landscape" makes the download progress and complete.
assetTitle is documented as:
> A human readable title for this asset in the user's preferred language. This value will be displayed in the usage pane of the Settings app.

But the language of the string seems to impact if download works.
Does anyone have experience to share ?

Accepted Reply

I believe that this is a bug in iOS10 and is fixed from iOS11.
In my case I will use romaji in iOS10 and the real title from iOS11.

Replies

The title was ばいせんふうけい in kanji.. Can't type it here for some reason...

The same problem is mentioned as a side note here:

https://forums.developer.apple.com/message/251742#251742

I believe that this is a bug in iOS10 and is fixed from iOS11.
In my case I will use romaji in iOS10 and the real title from iOS11.