Apache2 stopped but still showing 500 error on some browsers

Question

So I'm having an issue where a domain renders properly in one browser, but not in another. In this example, Chrome 74 loads the site fine, but Chrome 76 ends up rendering a 500 error.

Here is the thing; when I stop Apache, Chrome 74 renders a CloudFlare error saying the it couldn't reach the site. However, Chrome 76 still renders a 500 error.

After stopping Apache and checking with netstat, nothing should be listening on the port (80), and doesn't seem to be:

netstat -tlnpt
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       
PID/Program name
tcp        0      0 127.0.0.1:3306          0.0.0.0:*               LISTEN          1433/mysqld
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN          1448/sshd
tcp6       0      0 :::22                   :::*                    LISTEN          1448/sshd

This seems to be happening in Safari as well. This is a DigitalOcean droplet (Ubuntu 18.04.2) and it seems to be behind CloudFlare.

Since shutting down Apache2 doesn't seem to affect the 500 error some browsers show, I'm pretty far out of my domain. I've cleared browser cache/etc but no luck. I'm pretty lost.

Edit

Note that the domain resolves as an IPv6 address at port 80 in both browsers it is loading correctly and one's it isn't. I did find some people mentioning IPv6 as causing problems only in some browsers, but it didn't lead anywhere.

Edit

AND if I shutdown the server, I still get the 500 error in some browsers. Is this a CloudFlare edge server error perhaps?