Ошибка прокси vhost websocket конфигурация apache

Я пытаюсь настроить vhost websocket для своего apache. К сожалению, в Chrome появляется следующее сообщение об ошибке:

Proxy Error
The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request GET /.

Reason: Error reading from remote server

Журнал apache говорит так:

[Wed Sep 25 11:09:17.080534 2019] [proxy_http:error] [pid 28388:tid 140232636729088] (103)Software caused connection abort: [client 213.xx.xxx.xxx:16058] AH01102: error reading status line from remote server 46.xxx.xxx.xxx:8081, referer: https://fileexchanger.domain.de/
[Wed Sep 25 11:09:17.080615 2019] [proxy:error] [pid 28388:tid 140232636729088] [client 213.xx.xxx.xxx:16058] AH00898: Error reading from remote server returned by /favicon.ico, referer: https://fileexchanger.domain.de/

Моя консоль веб-разработчика выдает следующее сообщение об ошибке:

lufi-up.js:637 Mixed Content: The page at 'https://fileexchanger.domain.de/' was loaded over HTTPS, but attempted to connect to the insecure WebSocket endpoint 'ws://fileexchanger.domain.de/upload'. This request has been blocked; this endpoint must be available over WSS.
spawnWebsocket @ lufi-up.js:637
(anonymous) @ lufi-up.js:8
lufi-up.js:637 Uncaught DOMException: Failed to construct 'WebSocket': An insecure WebSocket connection may not be initiated from a page loaded over HTTPS.
    at spawnWebsocket (https://fileexchanger.domain.de/js/lufi-up.js:637:20)
    at https://fileexchanger.domain.de/js/lufi-up.js:8:13
spawnWebsocket @ lufi-up.js:637
(anonymous) @ lufi-up.js:8

Мой файл конфигурации apache:

<VirtualHost 46.4.xxx.xxx:443>
  ServerName fileexchanger.domain.de
  ServerAlias fileexchanger.domain.de
  DocumentRoot /srv/www/fileexchanger/home/www
  SSLProxyEngine on
  SSLEngine on
  SSLCertificateKeyFile /etc/ssl/private/name_df.key
  SSLCertificateFile    /etc/ssl/certs/name.de_df.crt
  SSLCertificateChainFile /etc/apache2/ssl.crt/namessl.crt
  #Protocols h2 h2c http/1.1

  RewriteEngine on
  RewriteCond ${HTTP:Upgrade} websocket [NC]
  RewriteCond ${HTTP:Connection} upgrade [NC]
  RewriteRule /(.*) "wss:/46.xxx.xxx.xxx:8081/$1" [P,L]

  ProxyRequests Off
  ProxyPreserveHost On
  #SSLProxyVerify none
  #SSLProxyCheckPeerCN off
  #SSLProxyCheckPeerName off
  #SSLProxyCheckPeerExpire off

  <Proxy *>
     Order deny,allow
     Allow from all
  </Proxy>

   <Location />
  ProxyPass https://46.xxx.xxx.xxx:8081/ timeout=7200
  ProxyPassReverse /
  LimitRequestBody 104857600
  </Location>
  ErrorLog /var/log/apache2/fileexchanger.domain.de/error.log
  CustomLog /var/log/apache2/fileexchanger.domain.de/access.log adelphi_vhost_combined

</VirtualHost>

Буду очень признателен за любые чаевые!

Спасибо Бавра