Application.streamingAssetsPath not pointing to OBB file (Samsung Galaxy S6)

I'm running a split Android application, so apk + obb. App is installed using Unity's build and run function, and this has worked fine on all of the devices I've tested on with the exception of the Samsung Galaxy S6.

I'm using the WWW class to extract assets from the OBB file, using Application.streamingAssetsPath, however this operation fails on the S6. I believe the reason is that streamingAssetsPath on the S6 points to the APK, and not the OBB.

Application.streamingAssetsPath = jar:file:///data/app/[app-ID]/base.apk!/​

... on the other test devices however ...

Application.streamingAssetsPath = jar:file:///storage/emulated/0/Android/obb/[app-ID]/main.1.[app-ID].obb!/
​

I've had a look around on the S6, and the OBB file is present on the device (under /mnt/shell/emulated/obb/), but hard-coding the full path in the app results in an access denied error.

Does anyone have any guidance on this issue? I'm thinking it could be an issue with the deployment procedure or some Samsung specific funny-business, but otherwise am drawing a blank at this stage.

 

I have the same problem using Nexus 7.