Not sure what is different here as we use LE/WinAcme for other sites on this server (as well as on other servers). I appreciate any help figuring this out. It's my first post so please let me know if I've left out pertinent information.
There are other sites being run and successfully accessed on that server. So, I know that port's open.
Here's where I got the IIS 10 number from:
I am our accidental SysAdmin and certainly not an expert in networking, web servers, certificates or any of it. So, I'm happy to confirm configuration settings or answer any questions that will help you help me.
As @rg305 says this version of IIS doesn't match Server 2019, it matches the much older Server 2012 R2 so I suspect you are looking on the wrong server. This would also explain why the validation is failing as the 2019 server you are on can't present the challenge response if the domain DNS isn't pointing to it.
So the server your domain is pointing to has the IP address 64.186.50.238 and is hosted by US Signal.
If the intent is to setup a new server for this website you'd need to update DNS first to point to the newer server (new being relative, 2022 would be the current version of Windows Server). You can open a browser on the desktop of the 2019 server and google "My IP address" to see what it seems to be externally.
Well, this is a little embarrassing. You guys are absolutely right! I only took over managing the DNS for this domain yesterday and was operating under some of my own (incorrect!) assumptions instead of checking to confirm.
There is an old (2012 R2) server I didn't realize was still running. Even thought the sites had been copied to, and are running on, the new server (from my screenshot), they obviously didn't have the appropriate DNS settings.