NGINX Reverse Proxy clientmaxbodysize ohne Wirkung

nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

server {
        listen 80;
        listen [::]:80;
        # redirect from htttp to https
        server_name xxxxxxxx;
        return 301 https://$server_name$request_uri;
}

server {
        listen 443 ssl;
        listen [::]:443 ssl;
        server_name xxxxxxxx;
        #Enable SSL
        # ssl on;
        ssl_certificate /etc/nginx/ssl/xxxxxxxx.pem;
        ssl_certificate_key /etc/nginx/ssl/xxxxxxxx.key;
        ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256:AES256+EECDH:AES256+EDH;
        ssl_protocols TLSv1.2 TLSv1.1 TLSv1;
        ssl_session_cache shared:SSL:10m;
        ssl_prefer_server_ciphers on;
        ssl_dhparam /etc/ssl/certs/dhparam.pem;
        add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload";  
        add_header X-Frame-Options DENY;
        add_header X-Content-Type-Options nosniff;
        proxy_http_version 1.1;
        proxy_pass_request_headers on;
        proxy_pass_header Date;
        proxy_pass_header Server;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        more_set_input_headers 'Authorization: $http_authorization';  
        proxy_set_header Accept-Encoding "";  
        more_set_headers -s 401 'WWW-Authenticate: Basic realm="xxxxxxxx"';  

       # location /owa           { proxy_pass https:{{comment_single_line_double_slash:1}}
       # location /OWA           { proxy_pass https:{{comment_single_line_double_slash:1}}
        location /EWS          { proxy_pass https://xxxxxxxx/EWS; }
        location /ews          { proxy_pass https://xxxxxxxx/EWS; }
        location /Microsoft-Server-ActiveSync { proxy_pass https://xxxxxxxx/Microsoft-Server-ActiveSync; }
        location /mapi           { proxy_pass https://xxxxxxxxx/mapi; }
        location /MAPI          { proxy_pass https://xxxxxxxx/mapi; }
        location /rpc           { proxy_pass https://xxxxxxxx/Rpc; }
        location /RPC           { proxy_pass https://xxxxxxxx/Rpc; }
        location /oab            { proxy_pass https://xxxxxxxx/OAB; }
        location /OAB            { proxy_pass https://xxxxxxxx/OAB; }
        location /autodiscover           { proxy_pass https://xxxxxxxx/Autodiscover; }
        location /Autodiscover           { proxy_pass https://xxxxxxxx/Autodiscover; }
  	
	client_max_body_size 100M;

        error_log /var/log/nginx/exchange-ssl-error.log;
        access_log /var/log/nginx/exchange-ssl-access.log;

}