WSS Secure WebSocket connection failed

I am trying to change my websocket connection to WSS and can't determine why it's not working.  I have obtained a keystore with the type JKS, which uses the same certificate as the website.  It is not self-signed.  Port 8543 is accessible when I try to test the connection.  Yet when I visit https://mywebsite.com,  my browser console says the WebSocket connection to wss://mywebsite.com:8543 failed.  I'm not sure where to go next for troubleshooting.