Cloudflare messing up nginx certbot SSL

Very very similar to issue here, but the solutions posted did not work for me.

I am using nginx as a reverse proxy on my home network in order to host a couple of websites. I have been using Cloudflare to manage my domain for a while, and am trying to get an nginx SSL setup for one of the things I am trying to host that requires https.

Like the linked post, DNS resolution works fine over just http.

I also did:

• Used certbox --nginx -d subdomain.example.com -d www.subdomain.example.com to get the certs where subdomain.example.com is replaced with my domain.
• sudo nginx -t
• sudo nginx -s reload

I do not have a ufw firewall.

My nginx config looks like this:

server {    listen 443 ssl;    listen [::]:443 ssl;    server_name subdomain.example.com www.subdomain.example.com;    location / {        proxy_pass http://192.168.0.103:5006;        include proxy_params;    }    ssl_certificate /etc/letsencrypt/live/subdomain.example.com/fullchain.pem; # managed by Certbot    ssl_certificate_key /etc/letsencrypt/live/subdomain.example.com/privkey.pem; # managed by Certbot    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot}server {    if ($host = www.subdomain.example.com) {        return 301 https://$host$request_uri;    } # managed by Certbot    if ($host = subdomain.example.com) {        return 301 https://$host$request_uri;    } # managed by Certbot    listen 80;    server_name subdomain.example.com www.subdomain.example.com;    return 404; # managed by Certbot}

When I go to another site (over http) that is on my reverse proxy, it works still, so I think my setup for the reverse proxy has not been messed up beyond the certs. When I try to go to subdomain.example.com, the connection just times out.

I have tried both enabling and disabling the traffic proxy on Cloudflare DNS, it did not seem to change anything (maybe it takes a while for the changes to take effect?). I also tried switching the Cloudflare SSL setting from Flexible -> Full, which also did not seem to change anything.

I am very new to setting up networks like this so it is highly likely that I missed something. Thoughts?