Soft 404 Problem

Hi,

A soft 404 occurs when your server returns a real page for a URL that doesn’t actually exist on your site. This usually happens when your server handles faulty or non-existent URLs as “OK,” and redirects the user to a valid page like the home page or a “custom” 404 page.
You need to contact your host provider and let theme know about this.
You can find more details and google’s instruction on how to deal with this 404 soft here: https://support.google.com/webmasters/answer/2409443?hl=en

Thanks