I have a problem with product attribute permalink showing 404 page not found.
(See : Settings > permalinks > Product attribute base option )
Example : http://epicomedia.com/vitrine-demo3/color/Black/
It shows 404 not found instead of a shop page filtered with black color.
You can test this with Twenty Seventeen theme which works fine for attribute archive page.
===How to enable archive for a product attribute===
Go to Attributes > color, edit the attribute, then enable the archive (there is an option), and finally re-save permalinks (Settings > permalinks).