Websocket proxy with SSL: connection to remote host was lost error

I'm trying to test out a secure websocket with SSL proxied with http-proxy in JS, but I'm getting the error:

"websocket._exceptions.WebSocketConnectionClosedException: Connection to remote host was lost."

I'm using Python websockets for the server side and websocket-client for the client side (since apparently websockets doesn't support proxies. All the files are in the same directory, and I want them to read from the same cert.pem and key.pem files to get the SSL information. I'd also like to use TLSv1.2 if possible. As a note, the proxy is there for logging purposes, to log the messages sent over the websocket connection, so they can't just be passed through encrypted.

wsserver.py:

...
async def server_main(PORT, ssl_context):
    async with websockets.serve(handler, "127.0.0.1", PORT, ssl=ssl_context):
        print('Server started')
        await asyncio.Future()

if __name__ == '__main__':
    print('Server starting...')
    PORT = 9003
    ssl_context = ssl.SSLContext(ssl.PROTOCOL_TLSv1_2) 
    ssl_context.load_cert_chain(pathlib.Path(__file__).with_name('cert.pem'), pathlib.Path(__file__).with_name('key.pem'), "asdf")
    asyncio.run(server_main(PORT, ssl_context))

wsclient.py:

...
async def client_main(PORT):
    websocket.enableTrace = True
    ssl_context = ssl.SSLContext(ssl.PROTOCOL_TLSv1_2)
    ssl_context.load_cert_chain(pathlib.Path(__file__).with_name('cert.pem'), pathlib.Path(__file__).with_name('key.pem'), "asdf")
    ws = websocket.create_connection(f"ws://localhost:{PORT}", sllopt={"context": ssl_context})

proxy.js:

...
var proxy = new httpProxy.createProxyServer({
    target: 'ws://localhost:9003',
    ws: true,
    ssl: {
        key: fs.readFileSync('key.pem', 'utf8'),
        cert: fs.readFileSync('cert.pem', 'utf8'),
        passphrase: "asdf"
    },
    secure: false
  }
...

I suspect the problem is in wsclient.py with the way I'm passing the ssl info in when creating the connection, but the websocket-client package documentation/examples are a little thin so I haven't been able to figure out where I'm going wrong.