Reverse proxy issues after 2022.03.01?

Configuration
1

I have been running HA (in virtual machine) behind Apache httpd reverse proxy without issues.
Starting yesterday (after upgrading to 2022.3.1?) I can no longer access HA using the reverse proxy. Accessing local HA url still works fine.

No (proxy) error in HA log.
In my Apache log:

[proxy:error](70007)The timeout specified has expired: AH00957: http: attempt to connect to <my_internal_ha_ip>:8123 (<my_internal_ha_ip>) failed
[proxy_http:error] [pid 28562] [client <my_external_ip>:61064] AH01114: HTTP: failed to make connection to backend: <my_internal_ha_ip>

The client <my_external_ip> mentioned in the Apache error is in the list of trusted_proxies of the HA config:

http:
  use_x_forwarded_for: true
  trusted_proxies:
    - <my_external_ip>
    - <my_internal_ip>

Suggestions?

To reproduce using curl (without having to provide token) I have created a test file in my www folder
(echo "test" >| config/www/test.txt)

Works:
curl -v http://homeassistant.local:8123/local/test.txt

Fails:
curl -v https://<my_external_url>/local/test.txt

(and the same for loading HA in the browser)

I don’t see a proxy related error in the HA log.
So, this error is NOT in the log:

ERROR (MainThread) [homeassistant.components.http.forwarded] A request from a reverse proxy was received from <an_ip_address>, but your HTTP integration is not set-up for reverse proxies

Using default logging level: warning

My Apache httpd config:

<VirtualHost *:443>
  ServerName <my_external_url>

  ProxyPreserveHost On
  ProxyRequests off

  ProxyPass / http://<my_internal_ha_ip>:8123/
  ProxyPassReverse / http://<my_internal_ha_ip>:8123/

  ProxyPass /api/websocket ws://<my_internal_ha_ip>:8123/api/websocket
  ProxyPassReverse /api/websocket ws://<my_internal_ha_ip>:8123/api/websocket

  RewriteEngine on
  RewriteCond %{HTTP:Upgrade} =websocket [NC]
  RewriteRule /(.*)  ws://<my_internal_ha_ip>:8123/$1 [P,l]
  RewriteCond %{HTTP:Upgrade} !=websocket [NC]
  RewriteRule /(.*)  http://<my_internal_ha_ip>:8123/$1 [P,l]

  CustomLog "/var/log/apache2/home_access_log" combinedvhost
  ErrorLog "/var/log/apache2/home_error_log"

# tried with X-Frame-Options, same result
  # Header set X-Frame-Options SAMEORIGIN

# tried with remoteip_module / X-Forwarded-For, same result
  #<IfModule remoteip_module>
  #  RemoteIPHeader X-Forwarded-For
  #  RemoteIPTrustedProxy <my_internal_ip> 
  #  # also tried:
  #  RemoteIPInternalProxy <my_internal_ip>
  #</IfModule>

SSLProxyEngine On

SSLCertificateFile /etc/letsencrypt/live/.../fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/.../privkey.pem
SSLCertificateChainFile /etc/letsencrypt/live/.../chain.pem
Include /etc/letsencrypt/options-ssl-apache.conf
</VirtualHost>