Certbot failing on bitwarden docker install

I have been using a self hosted Bitwarden docker running on Ubuntu 20.x server without any issues. Recently my ssl cert expired and the renewal failed. I never had issues with getting the certbot to run and issue a certificate previously and cannot determine what the issue is. I went as far as to spin up a clean Ubuntu Server install and a brand new Bitwarden install. Every time I get an unauthorized error; Detail: Invalid response from http://bitwarden.xxxxx.xxx/.well-known/acme-challenge/SEZzIXkKC9qXXCz3w1ik-QgGCgQMLZ_uUwScmhbuC5s [xx.xxx.xx.xx]: 503
FIrewall is open. Port 80 and 443 are redirected from my router using haproxy as a reverse pass thru proxy.
Installing Bitwarden with a self signed cert works and the server is accessible from the outside world on both port 80 and 443.
I cannot find any reason why the SSL install from the bitwarden.sh script fails like this during the letsencrypt process via certbot.
I get a Hint: The Certificate Authority couldn’t externally verify that the standalone plugin completed the required http-01 challenges. Ensure the plugin is configured correctly and that the changes it makes are accessible from the internet.

Any pointers, thoughts, troubleshooting tips will be greatly appreciated.