is the website actually created with the name webserver.bhsolutions.com, if it is, then the problem is simple, you haven't got that subdomain configured as an A record or CNAME record in your dns.
But the tutorial told you to create one for the server hostname, which is the subdomain. When you not create the website for the hostname as requested by the guide, then SSL cert configuration for the other services must fail. So, go back to the guide, create the website that you missed adding and enable SSL and let's encryot for it, wait a minute and then test if you can really reach that website of the server hostname and then proceed with the next steps of the tutorial.
in case this helps anyone. being that my server hostname is subdomain.domain.com i had to remove the auto subdomain from www. to none in the site settings in ispconfig. if i leave it with auto subdomain pointing to www. letsencrypt will not stay i also updated to 3.1.16 from 3.1.15 now letsencrypt works for the server and now i have secure emails etc... of course you need to make sure your dns points to your server before creating the site
The www autosubdomain would work, if you create in DNS entry for www.subdomain.domain.com pointing to your server.
speaking of 3.1.16, i remember seeing a post about 3 weeks ago saying it would be released by the end of the month (june). is there an updated timeframe for it's release (and the 20.04 perfect server tutorial)? not hassling/complaining about it, i know how things can go with complicated software and release schedules, would just be nice to know so that we can plan accordingly.
yes it is a production site. i read on here https://www.howtoforge.com/community/threads/lets-encrypt-error-faq.74179/ - Check that you have Let’s Encrypt (certbot) installed. ISPConfig 3.1.16 and newer will also support acme.sh as client. so i upgraded. but it seems to be working fine for now.