The child theme (Epik in this case) doesn’t affect SEO, it’s just the design. It’s the Genesis Framework that is responsible for the SEO/Markup etc. I’ve never heard of anything like this happening…..usually when people switch to Genesis their traffic increases due to the SEO features. Maybe there is something else going on, like a setting from your previous settings before you switched?
Sorry to hear about that! Hopefully it’s an easy fix.
Anyone else have any ideas?