Domain.com works, *.domain.com returns Bad Request, and www.domain.com does not connect

The site loads when I visit the droplet IP address and domain.com.

When I go to www.domain.com, Chrome reports:

This site can’t be reached
www.domain.com’s server IP address could not be found."

When I try *.domain.com, for instance dog.domain.com or giggles.domain.com, it responds with Bad Request (400). Same responses on MS Edge.

I’ve followed these links, amongst others:

How To Set Up Django with Postgres, Nginx, and Gunicorn on Ubuntu 16.04 How To Set Up and Test DNS Subdomains with DigitalOcean’s DNS Panel Subdomains not working with Digital Ocean DNS settings Why isn’t my site available via the www prefix?

I’m trying to deploy a Mezzanine 4.2.3 CMS using Ubuntu 16.04.3, Python 3.5.2, gunicorn, and nginx. I elected not to use the fabfile.py provided by Mezzanine because it didn’t work and I couldn’t figure out all the things that I had to attend to get it right. It was far easier to get domain.com running with the first DigitalOcean tutorial linked above.

I’ve placed the IP address, domain.com, *.domain.com, and www.domain.com in ALLOWED_HOSTS in local_settings.py (temporarily; will follow two scoops best practices once I get a better handle on deployment):

ALLOWED_HOSTS = [
    "domain.com",
    "*.domain.com",
    "www.domain.com",
    "IP address",
]

I’ve also placed them in /etc/nginx/sites-available/project:

server {
listen 80;
server_name [IP address] domain.com *.domain.com www.domain.com;

location = /favicon.ico { access_log off; log_not_found off; }
location /static/ {
root /home/project;
}

location / {
include proxy_params;
proxy_pass http://unix:/home/project/project.sock;
}
}

I’ve added an A record for domain.com pointing to the IP address of the droplet and it’s successful. When I go to the IP address or domain.com, the site shows.

Fearing conflicts, I tried these permutations:

Scenario 1: A:domain.com, *.domain.com

Scenario 2: A: domain.com, www.domain.com

Scenario 3: A: domain.com, www.domain.com, *domain.com

Scenario 4: A: domain.com CNAME: *.domain.com

Scenario 5: A: domain.com CNAME: www.domain.com

Scenario 6: A: domain.com, *.domain.com CNAME: *.domain.com

Scenario 7: A: domain.com, www.domain.com CNAME: www.domain.com

Scenario 8: A: domain.com, *.domain.com, www.domain.com CNAME: *.domain.com

Scenario 9: A: domain.com, *.domain.com, www.domain.com CNAME: www.domain.com

Scenario 10: A: domain.com, *.domain.com, www.domain.com CNAME: *.domain.com, www.domain.com

Scenario 11: A: domain.com CNAME: *.domain.com, www.domain.com

The results were the same for all 11 scenarios. I am leaving things at Scenario 11.

Along the way, I pinged the IP address, domain.com, *.domain.com, and www.domain.com from the command line. It’s always successful for the IP address, domain.com, and even *.domain.com. They invariably got a reply from the IP address. However, the response for www.domain.com:

Ping request could not find host www.domain.com. Please check the name and try again.

When I tried host <domain.com/www.domain.com/*.domain.com> +trace, it traced all the way down properly.

When I tried host <domain.com/www.domain.com/*.domain.com> ns1.digitalocean.com, it gave me the correct IP address.

I’m out of ideas. What could I have missed?