I was able to activate LetsEncrypt this morning without using the docker network that was created. For some reason, if I included that, then it would not work. Not sure what issues that will cause.
Regardless, I can see now why the interface is not exposed to the WWW. Changing the UI port resolves that issue!
I guess now it is time to try setup another docker on one of the subdomains and see if it accepts the SSL.
Thanks for your help.