Video Application.streamingAssetsPath

Couldn't get the new video player to work when built (works in editor), got a black screen instead of video on iOS.

However, I notice if I put the video in a regular folder (not streaming assets folder) and referenced it, the video plays fine on iOS.

So, is it necessary to still have a streaming assets folder, if so what is the way to link to the video?
I'm wondering if video's have to be put in memory rather than streamed if in a different folder - not sure, limited good information online.

Thanks.