Didn't get what you said?My sitemap is http into https within the subcategories.
So can you tell me what you can see in the "discovery" which is below the coverage, it may help to find where google find that http URL?
Seems like no discovery part in your case which I mention earlier. In that case it is little bit difficult to understand where that URL found by google.
You really should have your http redirect to the https version of your website - really unsure why you'd want to serve both of them.
Seems like no discovery part in your case which I mention earlier. In that case it is little bit difficult to understand where that URL found by google.