[onewaytrigger]

Yes there is.  In the slideshow section of the settings there is an option to include the root level fanart and folder files.  All that and more is explained on the Wiki page for AS (link in my sig). 😜  

 It was already toggled on but no luck. Anyway I read the wiki and it says the AS will copy the the fanart.png or folder.png to the extrafanart, but all my fanart are .jpg (the root and the obes on extrafanart) does it matters?  

No, the extension shouldn't matter. AS looks for .png, .jpg, .jpeg, and .gif files named fanart or folder.  If you post a log with debugging turned on for AS and Kodi with an artist who has the root level files, I can take a look.

 My bad again, I think I had to restart Kodi, but AS is including root level fanart on the slideshow. Pretty handy option because many less known artists/bands doesn't have extrafanarts.