This is killing any attempts to update the webadmin cert using the HTTP-01 challenge with Let's Encrypt. Not everyone has the capability of using the DNS challenge. There must be a better way.
I know this is an old question, but I'm trying to do this (via WAF) and I'm having some issues.
I've added the UTM itself as a real webserver and created a virtual one with HTTPS redirection. However, this doesn't work. Attempting to open the portal URL with HTTP still doesn't work, while the portal with HTTPS works.
I'm not sure what I did wrong.