The plain HTTP request was sent to HTTPS port

I am trying to put my docker nextcloud behind an nginx.

For the nginx i used the letsencrypt image from linuxserver but I used the official docker image for nextcloud.

this is my nginx config

server {
listen 443 default ssl http2 default_server;
listen [::]:443 ssl http2 default_server;

proxy_set_header X-FORWARDED-PROTO https;

root /config/www;
index index.html index.htm index.php;

server_name _;

ssl on;

# enable subfolder method reverse proxy confs
include /config/nginx/proxy-confs/*.subfolder.conf;

# all ssl related config moved to ssl.conf
include /config/nginx/ssl.conf;

# enable for ldap auth
#include /config/nginx/ldap.conf;

client_max_body_size 0;

location / {
	try_files $uri $uri/ /index.html /index.php?$args =404;

location ~ \.php$ {
	fastcgi_split_path_info ^(.+\.php)(/.+)$;
	fastcgi_index index.php;
	include /etc/nginx/fastcgi_params;

location = /.well-known/carddav {
    return 301 $scheme://$host/nextcloud/remote.php/dav;

location = /.well-known/caldav {
    return 301 $scheme://$host/nextcloud/remote.php/dav;

location /nextcloud {
    return 301 $scheme://$host/nextcloud/;

location ^~ /nextcloud/ {
    include /config/nginx/proxy.conf;
    resolver valid=30s;
    set $upstream_nextcloud nextcloud;
    rewrite /nextcloud(.*) $1 break;
    proxy_pass http://$upstream_nextcloud:80;
    proxy_max_temp_file_size 2048m;

    proxy_set_header Range $http_range;
    proxy_set_header If-Range $http_if_range;
    proxy_set_header Connection $http_connection;
    proxy_redirect off;
    proxy_ssl_session_reuse off;


As soon as I try to connect with the nextcloud client I get this message:
The plain HTTP request was sent to HTTPS port.

Any ideas?

No one has any ideas?