So I run our site (on Magento 2.2.3) thru an SEO checker and it flagged up an interesting issue:
The Accessible Index Page is Configured wrong.
Search engines see your https://www.xyz.co and https://www.xyz.co/index.html (or https://www.xyz.co/index.php) as different pages. With a variety of URLs, it's more challenging to get consolidated metrics for a specific piece of content. If you don't explicitly tell Google which URL is canonical, Google will make the choice for you, or might consider them both of equal weight, which might lead to unwanted behavior.
Is this actually an issue that can be fixed?
My understanding is that xyz.co./index.php is the 'real' URL, but that the index.php part is removed using the web server rewrites function in Magento backend.