Reverse Proxy over reverse proxy

Configuration
1

My home assistant runs on a synology VM. The synology does a reverse proxy around it and it is accessible fine from outside via https.

Now I want to do an additional reverse proxy to “standardize” the access for me from another server at an internet provider.

The login is working fine, but after that it complains that it has no connection to HA. What am I doing wrong?

<VirtualHost *:443>
        ServerName homeassistant.domain.tld
        ServerAdmin [email protected]

        ErrorLog <somewhere>
        CustomLog <somewhere>
[...]
SSLCertificateFile /etc/letsencrypt/live/domain.tld/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/domain.tld/privkey.pem
SSLProxyCheckPeerCN Off
SSLProxyEngine On

  ProxyPreserveHost Off
  ProxyPass / https://my_home:8124/
  ProxyPassReverse / https://my_home:8124/
2

Solved it. There was some RewriteRule missing for websocket wss, and it has to react on HTTPS, not HTTP.