We don’t really know why this post is there but inaccessible by you, but for anyone having this issue here’s how you can attempt to remove it.
You would go to any other post in your dashboard/admin, to edit it.
In your browser URL bar you’d look for this aspect of the URL:
post.php?post=xxxx&action=edit
Then, in a different browser tab, on the front end where you can see the problematic post, you want to go to the source code of that page using developer tools and in the <body> tag look in the class="" attribute for the following class:
postid-xxxx (The xxxx will be the post ID number.)
You want to take that number, go back to the post you can access and in the URL bar replace the number in post.php?post=xxxx&action=edit with the id number from the post you can’t access. (In this instance it was 2546, so post.php?post=2546&action=edit.)
Once you have this elusive post on your edit screen, you can delete it in the Publishing panel at the top right.
What this does though is move it to the ‘Trash’. So now on the main post list screen you’ll see ‘Trash(1)’ but if you click on ‘Trash’ you still may not see the post.
In the ‘Trash’ view though, you can click ‘Empty Trash’ and that will remove the mystery post permanently.
Now, we still don’t know what caused that post or why your admin account can’t access it, so keep an eye out for more of these, but at least it’s cleared out now.