How to stop Nginx redirect if HOST HEADER is incorrect - nginx

Question

I have been trying to solve this issue for quite awhile now. Bots are hitting my sites hard with INVALID HOST HEADERS and Nginx forwards these requests to Gunicorn/Django. I need to stop them at Nginx. I have tried every solution I can find on SO, and elsewhere, but none seem to work for my setup.
Nginx.conf:
upstream backend_server {
server backend:8000;
}
upstream backend_asgi {
server backend_asgi:8001;
}
server {
listen 80;
location /.well-known/acme-challenge/ {
root /var/www/certbot;
}
location ~* ^/(api|admin|static|v2) {
return 301 https://$host$request_uri;
}
location / {
return 301 https://$host$request_uri;
}
}
server {
listen 443 ssl;
listen [::]:443 ssl;
server_name example.site *.example.site;
ssl_certificate /etc/letsencrypt/live/example.site/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/example.site/privkey.pem;
include /etc/letsencrypt/options-ssl-nginx.conf;
ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;
location /ws/ {
proxy_pass http://backend_asgi;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Host $server_name;
}
location ~ ^/v2(?:/(.*))?$ {
root /usr/share/nginx/html;
index index.html;
try_files $uri $uri/ /v2/index.html =404;
}
location /backend_static/ {
alias /backend/assets/;
}
location /media/ {
alias /backend/media/;
}
location ~* ^/(api|admin) {
proxy_pass http://backend_server$request_uri;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $https;
proxy_connect_timeout 360s;
proxy_read_timeout 360s;
}
location / {
proxy_pass http://backend_server$request_uri;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $https;
proxy_connect_timeout 360s;
proxy_read_timeout 360s;
# Set upload size for videos to be 500MB
client_max_body_size 500M;
}
}
What can i add to my Nginx configuration to stop invalid host headers, given that I have a wildcard subdomain and bots are also using HOST HEADERS w/ subdomains?