No Cubemap Reflections at HTML Shader ?

Are Cubemaps not supported in HTML shading(Opengles2) or why cant i see Reflections of the enviroment on my objects even when the object is 100% glossy
First one with Shader Model5
Second with Mobile/HTML5

Is the second screenshot from in-editor feature level preview, or from actual HTML5 export? I notice that often the editor preview shows things different than actual HTML5 exports.

Also noticed that this was marked UE 4.8. Could you try latest 4.11 to see if that might have a difference? If it does, if you can post a minimal example (like you have now) as a zip and e.g. a debug or development built files, I could take a peek.

Another thing to note is to check out which WebGL extensions are supported on your browser: WebGL Caps Viewer - WebGL extensions and capabilities viewer | Geeks3D. In particular, I recall there was some interaction with the EXT_shader_texture_lod extension and reflections in UE4, so it would be good to check if that is supported on your system? Having downloadable build&project available somewhere would be good in comparing if it’s a browser rendering issue or an engine export issue.

I tested it now with the new version 4.11 and exported it to HTML still no reflections.
Down Below Exported HTML
WebGL extensions
and the zip file[link text][1]

Tried opening the zip file, but for some reason, I was unable to uncompress it with 7-zip or Windows file decompressor. I wonder if it might have gotten corrupted along the way(?)