Websocket port error when using wss web secure socket

I keep getting an error using wss:// even if I have Lets Encrypt setup. I am hoping someone could guide me to my error I cannot figure out.

I am using apache2 on Debian. I also have a working copy of Rocket Chat using wss://, and it is not causing any problems.

This is my partial apache2 used from the online docs

        # Set web sockets
        RewriteEngine On
        RewriteCond %{REQUEST_URI} /api/v[0-9]+/(users/)?websocket [NC]
        RewriteCond %{HTTP:UPGRADE} ^WebSocket$ [NC]
        RewriteCond %{HTTP:CONNECTION} \bUpgrade\b [NC]
        RewriteRule .* wss://{REQUEST_URI} [P,QSA,L]

        <Location />
                Require all granted
                ProxyPassReverseCookieDomain mattermost.domain.ca

        SSLEngine on
        SSLCertificateFile /etc/letsencrypt/live/domain.ca/cert.pem
        SSLCertificateKeyFile /etc/letsencrypt/live/domain.ca/privkey.pem
        SSLCACertificateFile /etc/letsencrypt/live/domain.ca/chain.pem
        SSLProtocol all -SSLv2 -SSLv3 -TLSv1 -TLSv1.1

Here is my partial json config

    "ServiceSettings": {
        "SiteURL": "https://mattermost.domain.ca",
        "WebsocketURL": "",
        "LicenseFileLocation": "",
        "ListenAddress": ":8065",
        "ConnectionSecurity": "",
        "TLSCertFile": "/etc/letsencrypt/live/domain.ca/cert.pem",
        "TLSKeyFile": "/etc/letsencrypt/live/domain.ca/privkey.pem",
        "TLSMinVer": "1.2",
        "TLSStrictTransport": false,
        "TLSStrictTransportMaxAge": 63072000,
        "TLSOverwriteCiphers": [],
        "UseLetsEncrypt": false,
        "LetsEncryptCertificateCacheFile": "./config/letsencrypt.cache",
        "Forward80To443": false,
        "TrustedProxyIPHeader": [

There are no errors in journalctl and no errors in the console->error logs. My let’s encrypt certificate does hold several domains, as this server holds several domains.

If I change the apache2 above and remove wss:// to ws:// there are no problems.