Cannot get websocket connection working with ec2 + application load balancer - amazon-web-services

Question

I am having trouble establishing a websocket connection. I have an aws ec2 instance that is running an SSL websocket server on a subdomain: api.example.com, on port 9999. My client application is running at www.example.com, the client sets up a listener:
new WebSocket('wss://api.example.com:9999');
This results in the browser giving me:
net::ERR_CONNECTION_REFUSED
So my next idea was since my application load balancer already has an https listener setup on port 443 going to my api server, I changed my websocket listener setup to:
new WebSocket('wss://api.example.com/socket');
Then I made my nodejs (restify) webserver on the ec2 instance catch /socket with plans to redirect it to localhost:9999... However, I put a console.log in that /socket endpoint prior to redirecting, and there is no logging happening-- I also tried wss://api.example.com:443/socket, neither seems to hit the endpoint in my webserver.
Yet if I use curl, it works fine:
~>curl -i -N -H "Connection: Upgrade" -H "Upgrade: websocket" -H "Host: api.example.com" -H "Origin: https://www.example.com" https://api.example.com/socket
HTTP/2 301
date: Tue, 26 Jun 2018 02:27:07 GMT
content-type: application/json
content-length: 4
location: https://localhost:9999/localhost
server: restify
access-control-allow-origin: https://www.example.com
vary: origin
access-control-expose-headers: api-version, content-length, content-md5, content-type, date, request-id, response-time
although https://localhost:9999/localhost seems a little weird-- but regardless, when I use curl, it hits the endpoint and I see the log.