That’s a sign of a misconfigured server. Considering that the site that shows up begins with an “a”, I’m led to believe that any requests the server can’t properly direct end up going to the first site on the list.
For now, I suggest you use the “Pause Cloudflare on Site” option from the Overview tab (lower right corner), then wait five minutes. Make sure your site loads correctly with HTTPS at the server before you UnPause Cloudflare.