This issue has been plaguing me for days and I cannot seem to solve it.
I recently wanted to help out a friend with their 'Let's Encrypt' issues, as the software was throwing out a 404 error for a certain file it needed. After some digging I discovered some DNS inconsistencies between which domain linked to what IP. Today I noticed that something really weird is going on. The set up looks like this:
https://websitename.com/ - 1st version of the website - Secure
https://www.websitename.com/ - 2nd version of the website - Not Secure
http://websitename.com/ - 1st version of the website - Not Secure
http://www.websitename.com/ - 3rd version of the website - Not Secure
I am not sure how something like this can even happen. By version of a website I mean an actual fully hosted website on a different IP.
I have not touched any of the htaccess files yet. I have checked all of the DNS settings for all of the given IPs but nothing seems to be wrong.
Sounds like the "www" CNAME record and the A record for the site are pointing to two different locations.
Just took a look at your DNS records. You have a record:
WWW record www.fish4parts.com A records are: www.fish4parts.com. A 91.121.225.216 [TTL=3600]
This record exists at ui-dns.com, which is separate from your fish4parts.com A Record.
If you cannot see the records on both of those NameServers (NS) you should give their support desk a call and ask them to remove the www A record from the ui-dns.com name server. If they are unresponsive you can always switch DNS providers at your domain. I use O365 for our domains, but previously used AWS Route53. The AWS product is super easy to use and very cheap.