SSL not working with self-signed certs

[pop-vapor]

The hass-configurator server is up on http://192.168.50.3:3218/ but not https://192.168.50.3:3218/

my settings.conf looks like:

{
    "BASEPATH": "../hass-config"
    "SSL_CERTIFICATE": "configurator.pem",
    "SSL_KEY": "privkey.pem"
}

I generated a self-signed cert+key pair with:
openssl req -sha256 -addext "subjectAltName = IP:X.X.X.X" -newkey rsa:4096 -nodes -keyout privkey.pem -x509 -days 730 -out configurator.pem and stuck the public and private keys in the same directory as the config file.

However even after this config I still cannot navigate to https://192.168.50.3:3218, I get the browser error:

Secure Connection Failed

An error occurred during a connection to 192.168.50.3:3218. SSL received a record that exceeded the maximum permissible length.

Error code: SSL_ERROR_RX_RECORD_TOO_LONG

What am I missing?

Edit: Additional note.
I get the html error whether or not I have the ssl cert and key lines in my config, so I assume that the error isn't actually related to my cert/key.

I've also used this exact same method to configure ssl for home assistant, which works with https