I don’t understand what you mean. I have don’t unpause CF I would not be able to run HTTPS as CF is the provider of that, so I will always get an error. When I tried to install WP with CF running I got a message during the installer that no trusted SSL cert. has been detected, but the installation carried on anyway.
I am on InfiniteFree hosting, so literally there is no way to communicate this with the host. They don’t provide support for free hosting customers. Only community. I cannot also find any settings in the CPanel to adjust in order to get any effect. I can request free SSL cert that last 90 days. But don’t see a point of that with CF. Been running free hosts before and had no problem enabling SSL.
I just don’t understand why the main domain would load, but anything then I got in redirect loop when going deeper. It just does not makes any sense to me, because it either works completely or not at all in my books. Can’t it be that there is some SSL settings which might interfere?
Right, the Origin certificate does not have the domain in the common name but in the SAN, but it’s still a valid certificate. If your host does not accept that, that’s unfortunately an issue on their side.
I’d contact them to clarify that and if that does not work you can always use a Let’s Encrypt certificate or whatever valid certificate they provide.
I am afraid that “tutorial” is wrong and provides incorrect advice. As already mentioned, a self-signed certificate can never provide a secure connection
As already written more than once, your current issues are because your site is not properly configured. Make sure it loads on HTTPS without Cloudflare, then it will work straight out of the box with Cloudflare as well.
If you do not have a valid certificate on your server, your site will be generally insecure and you will run into issues, as you already do.