lolc's questions

I own a website that uses a Let's Encrypt certificate. It's not behind Cloudflare, it's hosted at OVH and I'm accepting direct traffic from it.

Now, I set up an apache2 webserver and used certbot to automatically generate a certificate. The problem here is that when I look at the certificate information on Firefox, I can see at the bottom of the page that it contains references to "Cloudflare Nimbus2023", despite my not using their services.

The picture attached below is what it shows... (for some reason it won't let me attach pictures)

Can anyone explain to me what this is? What is Cloudflare accessing here??

I'm hosting a service on port 3000. Using apache, I made it so https://git.mywebsite.com proxies over to http://mywebsite.com:3000. Now, if I input the following command:

sudo iptables -A INPUT -p tcp --dport 3000 -j DROP

It does prevent external users from accessing http://mywebsite.com:3000, but now apache can no longer access it internally as well, which means https://git.mywebsite.com is down also. Is there a way to fix this?