400 Bad Request Rewriting HTTP to HTTPS not working

I am running an apache 2.4.25 on a Debian-Server. There is a website reachable via:

example.de and www.example.de 

they should be rewriten via configs and .htaccess to:

https://example.de https://www.example.de 

That does not work.

This lines where added by lets-encrypt into sites-enabled/000-default.conf, the commented lines where added by me to rewrite example.de to www.example.de but it does not work:

RewriteEngine on # rewrite example.de to www.example.de changed 11.11.2019 #RewriteCond %{HTTP_HOST} ^example\.de$ [NC] #RewriteRule (.*) https://www.example.de/$1 [R=301,L] #RewriteRule ^(.*)$ https://www.%{HTTP_HOST}/$1 [R=301] RewriteCond %{SERVER_NAME} =www.example.de RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent] 

SSL-config is written in 000-default-le-ssl.conf:

<IfModule mod_ssl.c> <VirtualHost *:443> ... <Directory /var/www/> Options -Indexes +FollowSymLinks AllowOverride all Order allow,deny allow from all </Directory> # added 01.04.2019 END <Directory /var/www/html/> Options -Indexes +FollowSymlinks AllowOverride All Require all granted allow from all </Directory> ... SSLEngine on Include /etc/letsencrypt/options-ssl-apache.conf Header always set Content-Security-Policy upgrade-insecure-requests SSLCertificateFile /etc/letsencrypt/live/www.example.de/fullchain.pem SSLCertificateKeyFile /etc/letsencrypt/live/www.example.de/privkey.pem 

There also is a wordpress.conf with virtual-host-entrys for port 80 and 443 literally containing the parts of default and default-ssl.conf.

The following is written in .htaccess:

# BEGIN WordPress <IfModule mod_rewrite.c> Options +FollowSymLinks RewriteEngine On RewriteBase / # rewrite example.de to www.example.de changed 11.11.2019 #RewriteCond %{HTTP_HOST} !^www\. #RewriteRule ^(.*)$ https://www.%{HTTP_HOST}/$1 [R=301] #RewriteCond %{SERVER_PORT} !=443 #RewriteRule ^(.*)$ https://www.example.de/$1 [R=301,L] RewriteCond %{HTTPS} !=on RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} RewriteRule îndex\.php$ - [L] # add a trailing slash to /wp-admin RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L] RewriteCond %{REQUEST_FILENAME} -f [OR] RewriteCond %{REQUEST_FILENAME} -d RewriteRule ^ - [L] RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L] RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L] RewriteRule . index.php [L] </IfModule> 

I took a look at the rewrite-entries in the error log: The rewrite-rules for rewriting to www or https dont appear there (loglevel debug rewrite:trace4).

When it was just a test-server rewriting from http to https worked like charm and now its live and it does not, while using https directly in browser works (the url changed by one character and the condition to rewrite example.de to www.example.de was added). I checked the modules; restarted the server; the servername = www.example.de, the serveralias = example.de;

I found this here on stackoverflow but nothing worked or does not apply to my case: https://stackoverflow.com/questions/17853828/redirecting-http-to-https-with-apache

Serving port 443 over http creates 400 Bad Request Error instead of redirect

Could somebody please help. I do not get it solved. Thanks in advance.