The source is from an addon within kodi builds. What is a bit strange is that before with 203 i had no issues with buffering. Now that i'm on 204 and same kodi + same build i'm having issues .
I thought it would be from add-ons. Streams (from internet) cannot be played with wrapper, so that's not a solution.
It's very strange that 2.0.3 had no problems but 2.0.4 does. They are similar.
My only suggestion (and you've probably done this already) is to disable Mediasurface (Surface) in Kodi. In Kodi, change settings level to Advanced and go Settings - Player - Videos - Allow hardware acceleration - Mediacodec (Surface): OFF.
Beyond that, I have reported the various reports of slower LAN performance in some apps to HiMedia, so they will be taking a look at it.